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L’aménagement réalisé par Agam pour l’Élysée répond à une commande faite à l’artiste par le chef de l’État en 1971. Excellent exemple d’espace pictural « cinétique » réalisé à l’échelle d’une pièce d’habitation et associant murs, plafonds, sol et portes d’entrée, le Salon porte à l’échelle de l’architecture intérieure les principes du « tableau polymorphique » réalisé à l’aide d’éléments colorés en biseau et offre au spectateur des compositions abstraites qui changent selon l’angle de vue que ce dernier adopte.
Aménagé entre 1972 et 1974 sous l’égide du Mobilier national, le Salon était encore inachevé au décès de Georges Pompidou en avril 1974. Il fut terminé et complété au cours de l’année par un tapis, réalisé par la Manufacture nationale des Gobelins d’après un carton de l’artiste, et par une sculpture mobile en acier inoxydable, également conçue par Agam. Après l’accession de Valéry Giscard d’Estaing à la présidence de la République, il fut démonté et entreposé avant d’être présenté de 1979 à 1984, puis de nouveau en janvier 2000, au Centre Pompidou.
Astéracée (ex Composée) de 20-60 cm, dressée, à latex abondant et poils en chapelet sur les parties végétatives jeunes. Feuilles fortement dentées et presque épineuses sur les marges, les inférieures profondément découpées, les caulinaires embrassant la tige par deux oreillettes en spirale. Inflorescence en corymbe lâche ou parfois presque en faisceau. Fleurs jaunes toutes ligulées de 2,5 cm, les extérieures un peu rougeâtres en dessous. Style et stigmates brun verdâtre. Akènes brunâtres, aplatis, à bordures larges et faces ornées de 3 nervures saillantes. Aigrette soyeuse et blanche, sessile.
Autres noms français : Laiteron âpre (cf. le nom scientifique d'espèce) ou épineux ou piquant (le nom de Laiteron provient du latex blanc renfermé dans la tige, tout comme celui scientifique de genre provenant à la fois du grec et du latin, désignant en général des "chardons" à suc laiteux). Espèce ubiquiste et polymorphe (surtout quant à la forme des feuilles et leur dentelure), nitrocline, commensale des cultures sarclées, mais qui s'observe au sein de nombreux autres milieux : friches pionnières, bermes, décombres, maraîchages et potagers (cf. H des Abbayes, H Coste et P Jauzein).
Faceted diamonds - "Cumulus" brooch with 8 carat diamond at top. (public display, Field Museum of Natural History, Chicago, Illinois, USA)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5200 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known (four of them are still unnamed). Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.
The element carbon occurs principally in its native state as graphite (C) and diamond (C). Graphite is the common & far less valuable polymorph of carbon. A scarce polymorph of carbon is diamond. The physical properties of diamond and graphite couldn’t be more different, considering they have the same chemistry. Diamond has a nonmetallic, adamantine luster, typically occurs in cubic or octahedral (double-pyramid) crystals, or subspherical to irregularly-shaped masses, and is extremely hard (H≡10). Diamonds can be almost any color, but are typically clearish, grayish, or yellowish. Many diamonds are noticeably fluorescent under black light (ultraviolet light), but the color and intensity of fluorescence varies. Some diamonds are phosphorescent - under certain conditions, they glow for a short interval on their own.
Very rarely, diamond is a rock-forming mineral (see diamondite - www.flickr.com/photos/jsjgeology/14618393527).
Chairlift @ Lollapalooza 2016, Grant Park, Chicago, IL, on Saturday, July 30, 2016.
Lollapalooza 2016 Setlist:
Look Up
Polymorphing
Amanaemonesia
I Belong in Your Arms
Show U Off
Romeo
Crying In Public
Moth to the Flame
Ch-Ching
Get Real
Faceted diamond, illuminated by one light source and showing the famous "fire" of gem-quality diamond. (4.75 mm across at its widest)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5200 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known (four of them are still unnamed). Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.
The element carbon occurs principally in its native state as graphite (C) and diamond (C). Graphite is the common & far less valuable polymorph of carbon. A scarce polymorph of carbon is diamond. The physical properties of diamond and graphite couldn’t be more different, considering they have the same chemistry. Diamond has a nonmetallic, adamantine luster, typically occurs in cubic or octahedral (double-pyramid) crystals, or subspherical to irregularly-shaped masses, and is extremely hard (H≡10). Diamonds can be almost any color, but are typically clearish, grayish, or yellowish. Many diamonds are noticeably fluorescent under black light (ultraviolet light), but the color and intensity of fluorescence varies. Some diamonds are phosphorescent - under certain conditions, they glow for a short interval on their own.
Very rarely, diamond is a rock-forming mineral (see diamondite - www.flickr.com/photos/jsjgeology/14618393527).
As borboletas são insectos da ordem Lepidoptera classificados nas super-famílias Hesperioidea e Papilionoidea, que constituem o grupo informal Rhopalocera.
As borboletas têm dois pares de asas membranosas cobertas de escamas e peças bucais adaptadas a sucção. Distinguem-se das traças (mariposas) pelas antenas rectilíneas que terminam numa bola, pelos hábitos de vida diurnos, pela metamorfose que decorre dentro de uma crisálida rígida e pelo abdómen fino e alongado. Quando em repouso, as borboletas dobram as suas asas para cima.
As borboletas são importantes polinizadores de diversas espécies de plantas.
O ciclo de vida das borboletas engloba as seguintes etapas:
1) ovo→ fase pré-larval
2) larva→ chamada também de lagarta ou taturana,
3) pupa→ que se desenvolve dentro da crisálida (ou casulo)
4) imago→ fase adulta
_______________________
A butterfly is any of several groups of mainly day-flying insects of the order Lepidoptera, the butterflies and moths. Like other holometabolous insects, butterflies' life cycle consists of four parts, egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. Butterflies comprise the true butterflies (superfamily Papilionoidea), the skippers (superfamily Hesperioidea) and the moth-butterflies (superfamily Hedyloidea). All the many other families within the Lepidoptera are referred to as moths.
Butterflies exhibit polymorphism, mimicry and aposematism. Some, like the Monarch, will migrate over long distances. Some butterflies have evolved symbiotic and parasitic relationships with social insects such as ants. Butterflies are important economically as agents of pollination. The caterpillars of some butterflies eat harmful insects. A few species are pests because in their larval stages they can damage domestic crops or trees. Culturally, butterflies are a popular motif in the visual and literary arts.
The 56 Full Sized Morphs Are:
01 Blaze a Trail | 02 Pearly King Morph | 03 The Messenger Morph | 04 The Power of Morphing Communication | 05 Morph Over, There's Room for Two! | 06 Morph into the Piñataverse | 07 Morpheus | 08 Apart Together | 09 London Parklife | 10 On Guard | 11 Mr Create | 12 Morph's Inspirational Dungarees | 13 Cactus Morph | 14 Forget-Me-Not | 15 Gingerbread Morph I 16 Totally Morphomatic! | 17 Dance-off Morph I 18 The Bard I 19 Mondrian Morph | 20 Morph Whizz Kidz Argonaut | 21 It's Raining Morphs! Halleujah! | 22 Messy Morph | 23 I Spy Morph | 24 Astromorph | 25 Make Your Mark | 26 Roll With It | 27 Morph and Friends Explore London | 28 Tartan Trailblazer | 29 London Collage | 30 Peace Love and Morph | 31 Midas Morph | 32 Freedom | 33 Good Vibes | 34 Tiger Morph | 35 Maximus Morpheus Londinium | 36 Chocks Away! | 37 Morph! It's the Wrong Trousers! | 38 Diverse-City | 39 Apples and Pears | 40 Morphlowers Please! | 41 Cyborg Morph | 42 Pride Morph | 43 The London Man | 44 Looking After the Ocean | 45 Rock Star! | 46 Wheelie | 47 Gentlemorph | 48 Polymorphism | 49 Whizz Bang! | 50 Stay Frosty | 51 Mmmmmmmoprh! | 52 Swashbuckler | 53 Morph Target | 54 Canary Morph | 55 Morph the Yeoman Guard | 56 Fish Ahoy!
The 23 Mini Morphs Are:
01 Neville | 02 Messy Morph | 03 Meta-MORPH-osis | 04 Morley the Morph - Ready to Board | 05 Near and Far | 06 Bright Ideas | 07 Creativity Rocks! | 08 Growing Together | 10 Many Hands Make Valence | 11 Mr. Tayo Shnubbub 'The Wellbeing Hero' | 12 Captain Compass I 13 Hands-On & Hands-Up | 14 This is Us | 15 The Adventures of Morph | 16 Our School | 17 Riverside Spirit | 18 Morpheby | 19 GRIT | 20 Happiness is an Inside Job | 21 Growing Together in Learning and in Faith | 22 Look for the Light I 23 Bringing Great Energy and Spirit to Make Things Happen
Obsidian in the Pleistocene of Wyoming, USA.
Obsidian is a glassy-textured, extrusive igneous rock. Glassy-textured rocks have no crystals at all. They form by very rapid cooling of lava or by cooling of high-viscosity lava. Most obsidians form by the latter. Obsidian can be felsic, intermediate, mafic, or alkaline in chemistry. Most are felsic to intermediate.
A famous locality in North America is Obsidian Cliff at Yellowstone, Wyoming. It is a Pleistocene-aged lava flow with the chemistry of rhyolite (= a light-colored, felsic, aphanitic, extrusive igneous rock). The cliff itself shows columnar jointing. The rocks principally range from aphyric rhyolitic obsidian to partially devitrified rhyolitic obsidian. Lithophysae are sometimes present. Extremely small, microscopic crystals are present - they can be seen in thin sections. Some samples are reported to have small olivine phenocrysts. Small clusters of crystals, composed of plagioclase feldspar, pyroxene, and olivine, are sometimes present.
Many of the whitish-colored spots and bands running through most Obsidian Cliff rock samples are areas of devitrification. Glass is unstable on geologic times scales and it slowly crystallizes. The light-colored spots and bands are now non-glassy. Spotted, partially devitrified obsidian is known by the rockhound term "snowflake obsidian" (see: www.flickr.com/photos/jsjgeology/16561606417). The spots are composed of silica (SiO2), but are not quartz. Rather, they are composed of a polymorph of quartz - cristobalite.
Stratigraphy: Roaring Mountain Member, Plateau Rhyolite, Upper Pleistocene, ~59 ka
Locality: loose boulder near the base of Obsidian Cliff, Yellowstone National Park, northwestern Wyoming, USA
----------------------
Age & some lithologic info. from:
Wooton (2010) - Age and Petrogenesis of the Roaring Mountain Rhyolites, Yellowstone Volcanic Field, Wyoming. M.S. thesis. University of Nevada at Las Vegas. 296 pp.
As borboletas são insectos da ordem Lepidoptera classificados nas super-famílias Hesperioidea e Papilionoidea, que constituem o grupo informal Rhopalocera.
As borboletas têm dois pares de asas membranosas cobertas de escamas e peças bucais adaptadas a sucção. Distinguem-se das traças (mariposas) pelas antenas rectilíneas que terminam numa bola, pelos hábitos de vida diurnos, pela metamorfose que decorre dentro de uma crisálida rígida e pelo abdómen fino e alongado. Quando em repouso, as borboletas dobram as suas asas para cima.
As borboletas são importantes polinizadores de diversas espécies de plantas.
O ciclo de vida das borboletas engloba as seguintes etapas:
1) ovo→ fase pré-larval
2) larva→ chamada também de lagarta ou taturana,
3) pupa→ que se desenvolve dentro da crisálida (ou casulo)
4) imago→ fase adulta
_______________________
A butterfly is any of several groups of mainly day-flying insects of the order Lepidoptera, the butterflies and moths. Like other holometabolous insects, butterflies' life cycle consists of four parts, egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. Butterflies comprise the true butterflies (superfamily Papilionoidea), the skippers (superfamily Hesperioidea) and the moth-butterflies (superfamily Hedyloidea). All the many other families within the Lepidoptera are referred to as moths.
Butterflies exhibit polymorphism, mimicry and aposematism. Some, like the Monarch, will migrate over long distances. Some butterflies have evolved symbiotic and parasitic relationships with social insects such as ants. Butterflies are important economically as agents of pollination. The caterpillars of some butterflies eat harmful insects. A few species are pests because in their larval stages they can damage domestic crops or trees. Culturally, butterflies are a popular motif in the visual and literary arts.
Récolté par Jules Cimon
Date de récolte : 08 / 07 / 2015
Substrat : vieille tige d’herbacée
Apothécie : jusqu’à 0,67 mm de diam., partiellement sessile, brune, plus claire vers la marge
Asques courtement à modérément cylindriques, parfois un peu sinueux vers la base, à 8 spores bisériées, avec crochet basal et appareil apical amyloïde, à contenu dextrinoïde, 33,5-43,8 x 4,7-5,7 µm
Paraphyses cylindriques, étroitement lancéolée-obtuses vers l’apex, non ramifiées, avec deux septa à la base, à contenu hyalin-jaunâtre et quelques petites guttules (exsiccatum), 35,3-43,8 x 2,4-2,7 µm, dépassant les asques de 4-7 µm
Spores cylindriques-fusoïdes, parfois légèrement courbes, lisses, à paroi mince, avec septum médian difficile à préciser et 2-3 petites guttules, hyalines, 6,7-8 x 1,6-2 µm, Q = 4,3
Medulla formée de cellules subglobuleuses à polymorphes, hyalines
Excipulum ectal en textura globulosa-angularis, formé de cellules à paroi épaissie, brun tabac foncé à légèrement olivâtre, 8,7-14,2 x 7,6-10 µm
Revêtement marginal formé de cellules terminales cylindriques à clavées, hyalines, 9,4-16,1 x 3,8-5,4 µm
Revêtement externe formé de cellules terminales globuleuses à ellipsoïdes, souvent caténulées, à paroi épaissie, brunes, 6,7-10,9 x 5,5-8,6 µm
Note : L’hyménium est couvert d’une substance adhérente, hyaline et réfringente.
Canon EOS 50D, Canon EF 100-400mm f/4,5-5,6 L IS USM, development in Lightroom.
Photographed on a birdwatchers' boat trip to the Farne Islands, Northumberland.
Uria aalge - Common Guillemot (Common Murre) - Trottellumme - Zeekoet - Guillemot de Troïl - Arao común - Uria - Sillgrissla - Lomvie - Nurzyk zwyczajny - . . .
Wikipedia (edited): "The common murre or common guillemot (Uria aalge) is a large auk. It has a circumpolar distribution, occurring in low-Arctic and boreal waters in the North Atlantic and North Pacific. It spends most of its time at sea, only coming to land to breed on rocky cliff shores or islands.
Guillemots are fast in direct flight but are not very agile. They can manoeuvre better underwater, where they typically dive to depths of 30–60m. They breed in colonies at high densities; nesting pairs may be in bodily contact with their neighbours. They make no nest; their single egg is incubated on a bare rock ledge on a cliff face.
Some individuals in the North Atlantic, known as "bridled guillemots", have a white ring around the eye extending back as a white line. This is not a distinct subspecies, but a polymorphism that becomes more common the farther north the birds breed."
en.wikipedia.org/wiki/Farne_Islands
Phosphorescing diamonds from an undisclosed locality. (each crystal is on the order of 0.5 millimeters in size)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are about 5600 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known. Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.
The element carbon occurs principally in its native state as graphite (C) and diamond (C). Graphite is the common & far less valuable polymorph of carbon. A scarce polymorph of carbon is diamond. The physical properties of diamond and graphite couldn’t be more different, considering they have the same chemistry. Diamond has a nonmetallic, adamantine luster, typically occurs in cubic or octahedral (double-pyramid) crystals, or subspherical to irregularly-shaped masses, and is extremely hard (H≡10). Diamonds can be almost any color, but are typically clearish, grayish, or yellowish. Many diamonds are noticeably fluorescent under black light (ultraviolet light), but the color and intensity of fluorescence varies. Some diamonds are phosphorescent - under certain conditions, they glow for a short interval on their own.
Very rarely, diamond is a rock-forming mineral (see diamondite - www.flickr.com/photos/jsjgeology/14618393527).
The diamonds shown above are clear/colorless under white light and glow blue, magenta, green, and other colors under black light (ultraviolet light; UV). This photo was taken just after a UV light was turned off - no external light source is present. The soft glowing green and blue colors are phosphorescence.
Diamond from Zaire, Africa. (7.23 carat-sized crystal; 1.3 centimeters across at its widest)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5200 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known (four of them are still unnamed). Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.
The element carbon occurs principally in its native state as graphite (C) and diamond (C). Graphite is the common & far less valuable polymorph of carbon. A scarce polymorph of carbon is diamond. The physical properties of diamond and graphite couldn’t be more different, considering they have the same chemistry. Diamond has a nonmetallic, adamantine luster, typically occurs in cubic or octahedral (double-pyramid) crystals, or subspherical to irregularly-shaped masses, and is extremely hard (H≡10). Diamonds can be almost any color, but are typically clearish, grayish, or yellowish. Many diamonds are noticeably fluorescent under black light (ultraviolet light), but the color and intensity of fluorescence varies. Some diamonds are phosphorescent - under certain conditions, they glow for a short interval on their own.
Very rarely, diamond is a rock-forming mineral (see diamondite - www.flickr.com/photos/jsjgeology/14618393527).
The Zaire specimen shown above is a 7.23 carat, dark-brown diamond mass that is a complex aggregate of several smaller diamond crystals. It comes from a late Late Cretaceous (65-79 Ma) kimberlite pipe in the Mbuji-Mayi Kimberlite Field. Most diamonds are considerably older than the host kimberlite.
Locality: Mbuji-Mayi Kimberlite Field, Kasai-Oriental Province, central Zaire ("D.R. Congo"), Africa
Vug with aragonite crystals in arenaceous, ferruginous, fossiliferous limestone from the Mississippian of Ohio, USA (photograph taken & provided by James Cheshire).
This unusual sedimentary rock has small vugs containing clear to whitish aragonite crystals (CaCO3 - calcium carbonate). Aragonite is a less common polymorph of calcite. Aragonite is rarely found in Ohio. The host rock is an arenaceous, ferruginous, fossiiferous limestone with dolomitized crinoid stem columnals. The dark brown material in the upper right portions of the vug is goethite (FeO·OH - iron hydroxy-oxide).
Stratigraphy: Vinton Member (horizon occurs at the boundary between massive, thick-bedded Vinton below & thin-bedded, flaggy Vinton above), upper Logan Formation, Osagean Stage, upper Lower Mississippian
Locality: Mt. Calvary Cemetery Outcrop - roadcut along eastern side of Jacksontown Road (Rt. 13), immediately adjacent to (east of) Mt. Calvary Catholic Cemetery, ~0.15 miles south of intersection with Hopewell Drive, Heath, south-central Licking County, east-central Ohio, USA (40° 02’ 00.8” North, 82° 24” 10.5” West)
Blijdorp, Rotterdam, Zoo
Butterflies are part of the class of Insects in the order Lepidoptera. Moths are also included in this order. Adults butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprise the true butterflies (superfamily Papilionoidea), the skippers (superfamily Hesperioidea) and the moth-butterflies (superfamily Hedyloidea). Other families within Lepidoptera are referred to as moths. Butterfly fossils date to the mid Eocene epoch, 40–50 million years ago.[1]
Butterflies exhibit polymorphism, mimicry and aposematism. Some, like the Monarch, will migrate over long distances. Some butterflies have and parasitic relationships with organisms including protozoans, flies, ants, other invertebrates, and vertebrates. [2] [3] Some species are pests because in their larval stages they can damage domestic crops or trees; however, some species are agents of pollination of some plants, and caterpillars of a few butterflies (e.g., Harvesters) eat harmful insects. Culturally, butterflies are a popular motif in the visual and literary arts.
The following minerals are found at Bristol Dry Lake:
• Anhydrite
• Antarcticite
• Calcite
• Celestine
• Gypsum
• Halite
Anhydrite
Formula: CaSO4
System: Orthorhombic
Colour:Colourless, bluish, ...
Lustre: Vitreous, Greasy, Pearly
Hardness: 3 - 3½
Name: Named from the Greek άυ-νδρος meaning "without" and "water", in alluson to the lack of water in the composition.
Isostructural with Ferruccite; isostructural and isomorphous with α-BaSO4 and α-SrSO4.
Antarcticite
Formula: CaCl2·6H2O
System: Trigonal
Colour: Colourless
Hardness: 2 - 3
Name: For its occurrence on the continent of Antarctica.
A highly hygroscopic mineral.
Calcite
Formula: CaCO3
System: Trigonal
Colour: White, Yellow, Red, ...
Lustre: Vitreous, Pearly
Hardness: 3
Name: From Calx, the Latin for Lime.
Polymorph of: Aragonite, Vaterite
Isostructural with: Nitratine, Otavite
A very common and widespread mineral with highly variable forms and colours. Calcite is best recognized by its relatively low hardness (H = 3) and its high reactivity with even weak acids, such as vinegar, plus its prominent cleavage in most varieties.
Celestine
Formula: SrSO4
System: Orthorhombic
Colour: Colourless, shades of ...
Hardness: 3 - 3½
Name: Named from the Greek "cœlestis," for celestial, in allusion to the faint blue color of the original specimen.
By far the most common strontium mineral.
Gypsum
Formula: Ca[SO4]·2H2O
System: Monoclinic
Colour: Colourless to white, ...
Hardness: 2
Name: Named in antiquity from the Greek "gypsos," meaning plaster.
Isostructural with: Brushite
Found as both massive material, including the alabaster variety; and clear crystals, the selenite variety; and, parallel fibrous, the satin spar variety. Typically white to clear, crystals thick tabular to lenticular, sometimes prismatic.
Halite
Formula: NaCl
System: Isometric
Colour: Colourless, whitish, ...
Lustre: Vitreous
Hardness: 2½
Name: From the Greek άλς, sea, for halites, later modified by J.D. Dana to halite.
Natural Salt. Occurs both as evaporite deposits in saline lakes and water courses, or as bedded sedimentary deposits, or as salt domes.
Source: www.mindat.org/loc-23697.html, An online information resource dedicated to providing free mineralogical information to all.
This photo is geo-tagged.
Bristol Lake, in Cadiz Valley, south of Amboy and the Bristol Mountains
20090301_0468-1a1_800x600
Diamond from Sierra Leone, West Africa. (public display, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5200 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known (four of them are still unnamed). Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.
The element carbon occurs principally in its native state as graphite (C) and diamond (C). Graphite is the common & far less valuable polymorph of carbon. A scarce polymorph of carbon is diamond. The physical properties of diamond and graphite couldn’t be more different, considering they have the same chemistry. Diamond has a nonmetallic, adamantine luster, typically occurs in cubic or octahedral (double-pyramid) crystals, or subspherical to irregularly-shaped masses, and is extremely hard (H≡10). Diamonds can be almost any color, but are typically clearish, grayish, or yellowish. Many diamonds are noticeably fluorescent under black light (ultraviolet light), but the color and intensity of fluorescence varies. Some diamonds are phosphorescent - under certain conditions, they glow for a short interval on their own.
Very rarely, diamond is a rock-forming mineral (see diamondite - www.flickr.com/photos/jsjgeology/14618393527).
Faceted diamonds - "Cumulus" brooch with 8 carat diamond at top. (public display, Field Museum of Natural History, Chicago, Illinois, USA)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5200 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known (four of them are still unnamed). Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.
The element carbon occurs principally in its native state as graphite (C) and diamond (C). Graphite is the common & far less valuable polymorph of carbon. A scarce polymorph of carbon is diamond. The physical properties of diamond and graphite couldn’t be more different, considering they have the same chemistry. Diamond has a nonmetallic, adamantine luster, typically occurs in cubic or octahedral (double-pyramid) crystals, or subspherical to irregularly-shaped masses, and is extremely hard (H≡10). Diamonds can be almost any color, but are typically clearish, grayish, or yellowish. Many diamonds are noticeably fluorescent under black light (ultraviolet light), but the color and intensity of fluorescence varies. Some diamonds are phosphorescent - under certain conditions, they glow for a short interval on their own.
Very rarely, diamond is a rock-forming mineral (see diamondite - www.flickr.com/photos/jsjgeology/14618393527).
Fluorescing diamonds from Russia (probably Siberia). (crystals are ~0.7 to 0.9 millimeters in size)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are about 5600 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known. Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.
The element carbon occurs principally in its native state as graphite (C) and diamond (C). Graphite is the common & far less valuable polymorph of carbon. A scarce polymorph of carbon is diamond. The physical properties of diamond and graphite couldn’t be more different, considering they have the same chemistry. Diamond has a nonmetallic, adamantine luster, typically occurs in cubic or octahedral (double-pyramid) crystals, or subspherical to irregularly-shaped masses, and is extremely hard (H≡10). Diamonds can be almost any color, but are typically clearish, grayish, or yellowish. Many diamonds are noticeably fluorescent under black light (ultraviolet light), but the color and intensity of fluorescence varies. Some diamonds are phosphorescent - under certain conditions, they glow for a short interval on their own.
Very rarely, diamond is a rock-forming mineral (see diamondite - www.flickr.com/photos/jsjgeology/14618393527).
The Russian diamonds shown above are clear/colorless under white light. This photo was taken under ultraviolet (UV) light - "black light", which makes the diamonds fluoresce various shades of blues and magentas and other colors.
Why do some minerals fluoresce under UV light? When short-wavelength UV radiation, long-wavelength UV radiation, or x-rays bombard atoms, electron excitation occurs. But the electrons do not remain in an energetically excited state. They quickly give off energy and resume their normal energy levels. If the electron energy release is in the visible spectrum of light, a mineral glows, or fluoresces.
Diamond from Sierra Leone, West Africa. (public display, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5200 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known (four of them are still unnamed). Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.
The element carbon occurs principally in its native state as graphite (C) and diamond (C). Graphite is the common & far less valuable polymorph of carbon. A scarce polymorph of carbon is diamond. The physical properties of diamond and graphite couldn’t be more different, considering they have the same chemistry. Diamond has a nonmetallic, adamantine luster, typically occurs in cubic or octahedral (double-pyramid) crystals, or subspherical to irregularly-shaped masses, and is extremely hard (H≡10). Diamonds can be almost any color, but are typically clearish, grayish, or yellowish. Many diamonds are noticeably fluorescent under black light (ultraviolet light), but the color and intensity of fluorescence varies. Some diamonds are phosphorescent - under certain conditions, they glow for a short interval on their own.
Very rarely, diamond is a rock-forming mineral (see diamondite - www.flickr.com/photos/jsjgeology/14618393527).
Diamonds from the Wyoming-Colorado border area, USA. (public display, Wyoming Geological Survey, Laramie, Wyoming, USA)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5400 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known. Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.
The element carbon occurs principally in its native state as graphite (C) and diamond (C). Graphite is the common & far less valuable polymorph of carbon. A scarce polymorph of carbon is diamond. The physical properties of diamond and graphite couldn’t be more different, considering they have the same chemistry. Diamond has a nonmetallic, adamantine luster, typically occurs in cubic or octahedral (double-pyramid) crystals, or subspherical to irregularly-shaped masses, and is extremely hard (H≡10). Diamonds can be almost any color, but are typically clearish, grayish, or yellowish. Many diamonds are noticeably fluorescent under black light (ultraviolet light), but the color and intensity of fluorescence varies. Some diamonds are phosphorescent - under certain conditions, they glow for a short interval on their own.
Very rarely, diamond is a rock-forming mineral (see diamondite - www.flickr.com/photos/jsjgeology/14618393527).
A decent number of kimberlite bodies have been identified in the Rocky Mountains along the Colorado-Wyoming border, forming the State Line Kimberlite Field. The field is traditionally considered to represent many kimberlite bodies emplaced at about the same time. Recent isotopic dating has indicated this is not the case.
Locality: undisclosed site accessible to Cominco American Incorporated
Gentiana is a genus of flowering plants belonging to the Gentian family (Gentianaceae), tribe Gentianeae and monophyletic subtribe Gentianinae. This a large genus, with about 400 species.
Gentiana frigidaThis is a cosmopolitan genus, occurring in alpine habitats of temperate regions of Asia, Europe and the Americas. Some species also occur in northwest Africa, eastern Australia and New Zealand. They consist of annual, biennial and perennial plants. Some are evergreen, others are not.
Gentians have opposite leaves that are sometimes arranged in a basal rosette, and trumpet-shaped flowers that are usually deep blue or azure, but may vary from white, creamy and yellow to red. Many species also show considerable polymorphism with respect to flower color. Typically, blue-flowered species predominate in the Northern Hemisphere, with red-flowered species dominant in the Andes (where bird pollination is probably more heavily favored by natural selection). White-flowered species are scattered throughout the range of the genus but dominate in New Zealand. All gentian species have terminal tubular flowers and most are pentamerous, i.e. with 5 corolla lobes (petals), and 5 sepals, but 4-7 in some species. The style is rather short or absent. The corolla shows folds (= plicae) between the lobes. The ovary is mostly sessile and has nectary glands.
Gentians are fully hardy and like full sun or partial shade, and neutral to acid soil that is rich in humus and well drained. They are popular in rock gardens.
According to Pliny the Elder, Gentian is an eponym of Gentius (180-168 BC), the King of Illyria, said to have discovered its healing properties. Some species are of medicinal use and their roots were harvested for the manufacture of tonic liquor, for instance in France "Suze" or similar liquors. Gentian is also used as a flavouring, for example in bitters, and the soft drink "Moxie" which contains "Gentian Root Extractives"
La Genziana (Gentiana) è un genere di piante della famiglia delle Gentianaceae, che comprende circa 400 specie.
Questo genere si trova un po' ovunque nell'habitat alpino delle regioni temperate dell'Asia, dell'Europa e del continente americano. Alcune specie si trovano anche nell'Africa nord-occidentale, nell'Australia orientale ed in Nuova Zelanda. Si tratta di piante annuali, biennali e perenni. Alcune sono sempreverdi, altre no. Sul versante italiano delle Alpi sono presenti diverse specie, che fioriscono durante l'estate. Sono quasi tutte "specie protette". Alcune specie si trovano anche sugli Appennini.
I fiori sono a forma di imbuto; il colore è più comunemente azzurro o blu scuro, ma può variare dal bianco, avorio e giallo al rosso. Le specie col fiore di colore blu predominano nell'emisfero settentrionale, quelle col fiore rosso sulle Ande; le specie a fiore bianco sono più rare, ma più frequenti in Nuova Zelanda.
Le genziane crescono su terreni acidi o neutri, ricchi di humus e ben drenati; si possono trovare in luoghi pienamente o parzialmente soleggiati.
Fonte : Vikipedia
Alpine wildflowers are among nature's greatest anomalies. They grow in some of the planet's harshest environments, though they appear as fragile as rice paper and are extremely vulnerable to hikers' boots.
These plants survive in the harsh alpine climate through adaptations like diminutive size, which keeps the plants' buds and stems below the worst weather and reduces their food needs. Some grow no more than an inch tall. Those that grow in dense cushions suffer less abuse from the wind. The dark leaves of plants like diapensia absorb heat from the sun efficiently. Many sedges and grasses are pliable enough to bend under strong winds, and produce their buds underground or near the ground. Some have adapted to photosynthesizing at colder temperatures. Most are perennial — they live more than one season. The alpine growing season is too short for most annuals, which finish their life cycle in one season.
I fiori alpini crescono in alcuni degli ambienti più duri del nostro pianeta.La natura li ha adattati a vivere in ambienti così ostili per la vita.Solo chi ama percorrere i sentieri di montagna nelle varie stagioni e specialmente in estate può conoscere l'intima gioia che l'improvvisa vista di un fiore tra le radure erbose o in mezzo alle rocce desta negli animi degli escursionisti. Non che questi fiori alpini, quasi tutti minuscoli, siano più belli o appariscenti di quelli dei giardini, tutt'altro, ma la loro presenza sovente in terreni e climi assai aspri, rappresenta sempre una gradita sorpresa o una rassicurante conferma: la natura, malgrado tutto, continua ad esprimere il meglio di se.
A termite is a small social insect that exhibits the most complex type of social life. Until recently, termites were ranked as an 'order' and classified in the order Isoptera, but they are currently placed in the order Blatidiae {(cockroaches)} with a valid epifamily Termi Toidae. Termites are also named as white ants which is incorrect. Termites are neither completely white nor ants. These are soft yellow or brown colored insects. These insects living in a colony, i.e., living in a colony, show systematic species or polymorphism. A colony can contain anywhere from thousands to millions of members. Each colony contains military insects, worker or worker insects, nymphs, and reproductive members of both sexes. The worker insects build the bambi or nest. The habitats of termites not only have a safe living arrangement, but also have a system of water conservation. Wood is the main food of termites. Their jaws are capable of cutting wood.
Ipê Amarelo, Tabebuia [chrysotricha or ochracea].
Ipê-amarelo em Brasília, Brasil.
This tree is in Brasília, Capital of Brazil.
Text, in english, from Wikipedia, the free encyclopedia
"Trumpet tree" redirects here. This term is occasionally used for the Shield-leaved Pumpwood (Cecropia peltata).
Tabebuia
Flowering Araguaney or ipê-amarelo (Tabebuia chrysantha) in central Brazil
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Lamiales
Family: Bignoniaceae
Tribe: Tecomeae
Genus: Tabebuia
Gomez
Species
Nearly 100.
Tabebuia is a neotropical genus of about 100 species in the tribe Tecomeae of the family Bignoniaceae. The species range from northern Mexico and the Antilles south to northern Argentina and central Venezuela, including the Caribbean islands of Hispaniola (Dominican Republic and Haiti) and Cuba. Well-known common names include Ipê, Poui, trumpet trees and pau d'arco.
They are large shrubs and trees growing to 5 to 50 m (16 to 160 ft.) tall depending on the species; many species are dry-season deciduous but some are evergreen. The leaves are opposite pairs, complex or palmately compound with 3–7 leaflets.
Tabebuia is a notable flowering tree. The flowers are 3 to 11 cm (1 to 4 in.) wide and are produced in dense clusters. They present a cupular calyx campanulate to tubular, truncate, bilabiate or 5-lobed. Corolla colors vary between species ranging from white, light pink, yellow, lavender, magenta, or red. The outside texture of the flower tube is either glabrous or pubescentThe fruit is a dehiscent pod, 10 to 50 cm (4 to 20 in.) long, containing numerous—in some species winged—seeds. These pods often remain on the tree through dry season until the beginning of the rainy.
Species in this genus are important as timber trees. The wood is used for furniture, decking, and other outdoor uses. It is increasingly popular as a decking material due to its insect resistance and durability. By 2007, FSC-certified ipê wood had become readily available on the market, although certificates are occasionally forged.
Tabebuia is widely used as ornamental tree in the tropics in landscaping gardens, public squares, and boulevards due to its impressive and colorful flowering. Many flowers appear on still leafless stems at the end of the dry season, making the floral display more conspicuous. They are useful as honey plants for bees, and are popular with certain hummingbirds. Naturalist Madhaviah Krishnan on the other hand once famously took offense at ipé grown in India, where it is not native.
Lapacho teaThe bark of several species has medical properties. The bark is dried, shredded, and then boiled making a bitter or sour-tasting brownish-colored tea. Tea from the inner bark of Pink Ipê (T. impetiginosa) is known as Lapacho or Taheebo. Its main active principles are lapachol, quercetin, and other flavonoids. It is also available in pill form. The herbal remedy is typically used during flu and cold season and for easing smoker's cough. It apparently works as expectorant, by promoting the lungs to cough up and free deeply embedded mucus and contaminants. However, lapachol is rather toxic and therefore a more topical use e.g. as antibiotic or pesticide may be advisable. Other species with significant folk medical use are T. alba and Yellow Lapacho (T. serratifolia)
Tabebuia heteropoda, T. incana, and other species are occasionally used as an additive to the entheogenic drink Ayahuasca.
Mycosphaerella tabebuiae, a plant pathogenic sac fungus, was first discovered on an ipê tree.
Tabebuia alba
Tabebuia anafensis
Tabebuia arimaoensis
Tabebuia aurea – Caribbean Trumpet Tree
Tabebuia bilbergii
Tabebuia bibracteolata
Tabebuia cassinoides
Tabebuia chrysantha – Araguaney, Yellow Ipê, tajibo (Bolivia), ipê-amarelo (Brazil), cañaguate (N Colombia)
Tabebuia chrysotricha – Golden Trumpet Tree
Tabebuia donnell-smithii Rose – Gold Tree, "Prima Vera", Cortez blanco (El Salvador), San Juan (Honduras), palo blanco (Guatemala),duranga (Mexico)
A native of Mexico and Central Americas, considered one of the most colorful of all Central American trees. The leaves are deciduous. Masses of golden-yellow flowers cover the crown after the leaves are shed.
Tabebuia dubia
Tabebuia ecuadorensis
Tabebuia elongata
Tabebuia furfuracea
Tabebuia geminiflora Rizz. & Mattos
Tabebuia guayacan (Seem.) Hemsl.
Tabebuia haemantha
Tabebuia heptaphylla (Vell.) Toledo – tajy
Tabebuia heterophylla – roble prieto
Tabebuia heteropoda
Tabebuia hypoleuca
Tabebuia impetiginosa – Pink Ipê, Pink Lapacho, ipê-cavatã, ipê-comum, ipê-reto, ipê-rosa, ipê-roxo-damata, pau d'arco-roxo, peúva, piúva (Brazil), lapacho negro (Spanish); not "brazilwood"
Tabebuia incana
Tabebuia jackiana
Tabebuia lapacho – lapacho amarillo
Tabebuia orinocensis A.H. Gentry[verification needed]
Tabebuia ochracea
Tabebuia oligolepis
Tabebuia pallida – Cuban Pink Trumpet Tree
Tabebuia platyantha
Tabebuia polymorpha
Tabebuia rosea (Bertol.) DC.[verification needed] (= T. pentaphylla (L.) Hemsley) – Pink Poui, Pink Tecoma, apama, apamate, matilisguate
A popular street tree in tropical cities because of its multi-annular masses of light pink to purple flowers and modest size. The roots are not especially destructive for roads and sidewalks. It is the national tree of El Salvador and the state tree of Cojedes, Venezuela
Tabebuia roseo-alba – White Ipê, ipê-branco (Brazil), lapacho blanco
Tabebuia serratifolia – Yellow Lapacho, Yellow Poui, ipê-roxo (Brazil)
Tabebuia shaferi
Tabebuia striata
Tabebuia subtilis Sprague & Sandwith
Tabebuia umbellata
Tabebuia vellosoi Toledo
Ipê-do-cerrado
Texto, em português, da Wikipédia, a enciclopédia livre.
Ipê-do-cerrado
Classificação científica
Reino: Plantae
Divisão: Magnoliophyta
Classe: Magnoliopsida
Subclasse: Asteridae
Ordem: Lamiales
Família: Bignoniaceae
Género: Tabebuia
Espécie: T. ochracea
Nome binomial
Tabebuia ochracea
(Cham.) Standl. 1832
Sinónimos
Bignonia tomentosa Pav. ex DC.
Handroanthus ochraceus (Cham.) Mattos
Tabebuia chrysantha (Jacq.) G. Nicholson
Tabebuia hypodictyon A. DC.) Standl.
Tabebuia neochrysantha A.H. Gentry
Tabebuia ochracea subsp. heteropoda (A. DC.) A.H. Gentry
Tabebuia ochracea subsp. neochrysantha (A.H. Gentry) A.H. Gentry
Tecoma campinae Kraenzl.
ecoma grandiceps Kraenzl.
Tecoma hassleri Sprague
Tecoma hemmendorffiana Kraenzl.
Tecoma heteropoda A. DC.
Tecoma hypodictyon A. DC.
Tecoma ochracea Cham.
Ipê-do-cerrado é um dos nomes populares da Tabebuia ochracea (Cham.) Standl. 1832, nativa do cerrado brasileiro, no estados de Amazonas, Pará, Maranhão, Piauí, Ceará, Pernambuco, Bahia, Espírito Santo, Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Rio de Janeiro, São Paulo e Paraná.
Está na lista de espécies ameaçadas do estado de São Paulo, onde é encontrda também no domínio da Mata Atlântica[1].
Ocorre também na Argentina, Paraguai, Bolívia, Equador, Peru, Venezuela, Guiana, El Salvador, Guatemala e Panamá[2].
Há uma espécie homônima descrita por A.H. Gentry em 1992.
Outros nomes populares: ipê-amarelo, ipê-cascudo, ipê-do-campo, ipê-pardo, pau-d'arco-do-campo, piúva, tarumã.
Características
Altura de 6 a 14 m. Tronco tortuso com até 50 cm de diâmetro. Folhas pilosas em ambas as faces, mais na inferior, que é mais clara.
Planta decídua, heliófita, xerófita, nativa do cerrado em solos bem drenados.
Floresce de julho a setembro. Os frutos amadurecem de setembro a outubro.
FloresProduz grande quantidade de sementes leves, aladas com pequenas reservas, e que perdem a viabilidade em menos de 90 dias após coleta. A sua conservação vem sendo estudada em termos de determinação da condição ideal de armazenamento, e tem demonstrado a importância de se conhecer o comportamento da espécie quando armazenada com diferentes teores de umidade inicial, e a umidade de equilíbrio crítica para a espécie (KANO; MÁRQUEZ & KAGEYAMA, 1978). As levíssimas sementes aladas da espécie não necessitam de quebra de dormência. Podem apenas ser expostas ao sol por cerca de 6 horas e semeadas diretamente nos saquinhos. A germinação ocorre após 30 dias e de 80%. As sementes são ortodoxas e há aproximadamente 72 000 sementes em cada quilo.
O desenvolvimento da planta é rápido.
Como outros ipês, a madeira é usada em tacos, assoalhos, e em dormentes e postes. Presta-se também para peças torneadas e instrumento musicais.
Tabebuia alba (Ipê-Amarelo)
Texto, em português, produzido pela Acadêmica Giovana Beatriz Theodoro Marto
Supervisão e orientação do Prof. Luiz Ernesto George Barrichelo e do Eng. Paulo Henrique Müller
Atualizado em 10/07/2006
O ipê amarelo é a árvore brasileira mais conhecida, a mais cultivada e, sem dúvida nenhuma, a mais bela. É na verdade um complexo de nove ou dez espécies com características mais ou menos semelhantes, com flores brancas, amarelas ou roxas. Não há região do país onde não exista pelo menos uma espécie dele, porém a existência do ipê em habitat natural nos dias atuais é rara entre a maioria das espécies (LORENZI,2000).
A espécie Tabebuia alba, nativa do Brasil, é uma das espécies do gênero Tabebuia que possui “Ipê Amarelo” como nome popular. O nome alba provém de albus (branco em latim) e é devido ao tomento branco dos ramos e folhas novas.
As árvores desta espécie proporcionam um belo espetáculo com sua bela floração na arborização de ruas em algumas cidades brasileiras. São lindas árvores que embelezam e promovem um colorido no final do inverno. Existe uma crença popular de que quando o ipê-amarelo floresce não vão ocorrer mais geadas. Infelizmente, a espécie é considerada vulnerável quanto à ameaça de extinção.
A Tabebuia alba, natural do semi-árido alagoano está adaptada a todas as regiões fisiográficas, levando o governo, por meio do Decreto nº 6239, a transformar a espécie como a árvore símbolo do estado, estando, pois sob a sua tutela, não mais podendo ser suprimida de seus habitats naturais.
Taxonomia
Família: Bignoniaceae
Espécie: Tabebuia Alba (Chamiso) Sandwith
Sinonímia botânica: Handroanthus albus (Chamiso) Mattos; Tecoma alba Chamisso
Outros nomes vulgares: ipê-amarelo, ipê, aipê, ipê-branco, ipê-mamono, ipê-mandioca, ipê-ouro, ipê-pardo, ipê-vacariano, ipê-tabaco, ipê-do-cerrado, ipê-dourado, ipê-da-serra, ipezeiro, pau-d’arco-amarelo, taipoca.
Aspectos Ecológicos
O ipê-amarelo é uma espécie heliófita (Planta adaptada ao crescimento em ambiente aberto ou exposto à luz direta) e decídua (que perde as folhas em determinada época do ano). Pertence ao grupo das espécies secundárias iniciais (DURIGAN & NOGUEIRA, 1990).
Abrange a Floresta Pluvial da Mata Atlântica e da Floresta Latifoliada Semidecídua, ocorrendo principalmente no interior da Floresta Primária Densa. É característica de sub-bosques dos pinhais, onde há regeneração regular.
Informações Botânicas
Morfologia
As árvores de Tabebuia alba possuem cerca de 30 metros de altura. O tronco é reto ou levemente tortuoso, com fuste de 5 a 8 m de altura. A casca externa é grisáceo-grossa, possuindo fissuras longitudinais esparas e profundas. A coloração desta é cinza-rosa intenso, com camadas fibrosas, muito resistentes e finas, porém bem distintas.
Com ramos grossos, tortuosos e compridos, o ipê-amarelo possui copa alongada e alargada na base. As raízes de sustentação e absorção são vigorosas e profundas.
As folhas, deciduais, são opostas, digitadas e compostas. A face superior destas folhas é verde-escura, e, a face inferior, acinzentada, sendo ambas as faces tomentosas. Os pecíolos das folhas medem de 2,5 a 10 cm de comprimento. Os folíolos, geralmente, apresentam-se em número de 5 a 7, possuindo de 7 a 18 cm de comprimento por 2 a 6 cm de largura. Quando jovem estes folíolos são densamente pilosos em ambas as faces. O ápice destes é pontiagudo, com base arredondada e margem serreada.
As flores, grandes e lanceoladas, são de coloração amarelo-ouro. Possuem em média 8X15 cm.
Quanto aos frutos, estes possuem forma de cápsula bivalvar e são secos e deiscentes. Do tipo síliqua, lembram uma vagem. Medem de 15 a 30 cm de comprimento por 1,5 a 2,5 cm de largura. As valvas são finamente tomentosas com pêlos ramificados. Possuem grande quantidade de sementes.
As sementes são membranáceas brilhantes e esbranquiçadas, de coloração marrom. Possuem de 2 a 3 cm de comprimento por 7 a 9 mm de largura e são aladas.
Reprodução
A espécie é caducifólia e a queda das folhas coincide com o período de floração. A floração inicia-se no final de agosto, podendo ocorrer alguma variação devido a fenômenos climáticos. Como a espécie floresce no final do inverno é influenciada pela intensidade do mesmo. Quanto mais frio e seco for o inverno, maior será a intensidade da florada do ipê amarelo.
As flores por sua exuberância, atraem abelhas e pássaros, principalmente beija-flores que são importantes agentes polinizadores. Segundo CARVALHO (2003), a espécie possui como vetor de polinização a abelha mamangava (Bombus morio).
As sementes são dispersas pelo vento.
A planta é hermafrodita, e frutifica nos meses de setembro, outubro, novembro, dezembro, janeiro e fevereiro, dependendo da sua localização. Em cultivo, a espécie inicia o processo reprodutivo após o terceiro ano.
Ocorrência Natural
Ocorre naturalmente na Floresta Estaciobal Semidecicual, Floresta de Araucária e no Cerrado.
Segundo o IBGE, a Tabebuia alba (Cham.) Sandw. é uma árvore do Cerrado, Cerradão e Mata Seca. Apresentando-se nos campos secos (savana gramíneo-lenhosa), próximo às escarpas.
Clima
Segundo a classificação de Köppen, o ipê-amarelo abrange locais de clima tropical (Aw), subtropical úmido (Cfa), sutropical de altitude (Cwa e Cwb) e temperado.
A T.alba pode tolerar até 81 geadas em um ano. Ocorre em locais onde a temperatura média anual varia de 14,4ºC como mínimo e 22,4ºC como máximo.
Solo
A espécie prefere solos úmidos, com drenagem lenta e geralmente não muito ondulados (LONGHI, 1995).
Aparece em terras de boa à média fertilidade, em solos profundos ou rasos, nas matas e raramente cerradões (NOGUEIRA, 1977).
Pragas e Doenças
De acordo com CARVALHO (2003), possui como praga a espécie de coleópteros Cydianerus bohemani da família Curculionoideae e um outro coleóptero da família Chrysomellidae. Apesar da constatação de elevados índices populacionais do primeiro, os danos ocasionados até o momento são leves. Nas praças e ruas de Curitiba - PR, 31% das árvores foram atacadas pela Cochonilha Ceroplastes grandis.
ZIDKO (2002), ao estudar no município de Piracicaba a associação de coleópteros em espécies arbóreas, verificou a presença de insetos adultos da espécie Sitophilus linearis da família de coleópteros, Curculionidae, em estruturas reprodutivas. Os insetos adultos da espécie emergiram das vagens do ipê, danificando as sementes desta espécie nativa.
ANDRADE (1928) assinalou diversas espécies de Cerambycidae atacando essências florestais vivas, como ingazeiro, cinamomo, cangerana, cedro, caixeta, jacarandá, araribá, jatobá, entre outras como o ipê amarelo.
A Madeira
A Tabebuia alba produz madeira de grande durabilidade e resistência ao apodrecimento (LONGHI,1995).
MANIERI (1970) caracteriza o cerne desta espécie como de cor pardo-havana-claro, pardo-havan-escuro, ou pardo-acastanhado, com reflexos esverdeados. A superfície da madeira é irregularmente lustrosa, lisa ao tato, possuindo textura media e grã-direita.
Com densidade entre 0,90 e 1,15 grama por centímetro cúbico, a madeira é muito dura (LORENZI, 1992), apresentando grande dificuldade ao serrar.
A madeira possui cheiro e gosto distintos. Segundo LORENZI (1992), o cheiro característico é devido à presença da substância lapachol, ou ipeína.
Usos da Madeira
Sendo pesada, com cerne escuro, adquire grande valor comercial na marcenaria e carpintaria. Também é utilizada para fabricação de dormentes, moirões, pontes, postes, eixos de roda, varais de carroça, moendas de cana, etc.
Produtos Não-Madeireiros
A entrecasca do ipê-amarelo possui propriedades terapêuticas como adstringente, usada no tratamento de garganta e estomatites. É também usada como diurético.
O ipê-amarelo possui flores melíferas e que maduras podem ser utilizadas na alimentação humana.
Outros Usos
É comumente utilizada em paisagismo de parques e jardins pela beleza e porte. Além disso, é muito utilizada na arborização urbana.
Segundo MOREIRA & SOUZA (1987), o ipê-amarelo costuma povoar as beiras dos rios sendo, portanto, indicado para recomposição de matas ciliares. MARTINS (1986), também cita a espécie para recomposição de matas ciliares da Floresta Estacional Semidecidual, abrangendo alguns municípios das regiões Norte, Noroeste e parte do Oeste do Estado do Paraná.
Aspectos Silviculturais
Possui a tendência a crescer reto e sem bifurcações quando plantado em reflorestamento misto, pois é espécie monopodial. A desrrama se faz muito bem e a cicatrização é boa. Sendo assim, dificilmente encopa quando nova, a não ser que seja plantado em parques e jardins.
Ao ser utilizada em arborização urbana, o ipê amarelo requer podas de condução com freqüência mediana.
Espécie heliófila apresenta a pleno sol ramificação cimosa, registrando-se assim dicotomia para gema apical. Deve ser preconizada, para seu melhor aproveitamento madeireiro, podas de formação usuais (INQUE et al., 1983).
Produção de Mudas
A propagação deve realizada através de enxertia.
Os frutos devem ser coletados antes da dispersão, para evitar a perda de sementes. Após a coleta as sementes são postas em ambiente ventilado e a extração é feita manualmente. As sementes do ipê amarelo são ortodoxas, mantendo a viabilidade natural por até 3 meses em sala e por até 9 meses em vidro fechado, em câmara fria.
A condução das mudas deve ser feita a pleno sol. A muda atinge cerca de 30 cm em 9 meses, apresentando tolerância ao sol 3 semanas após a germinação.
Sementes
Os ipês, espécies do gênero Tabebuia, produzem uma grande quantidade de sementes leves, aladas com pequenas reservas, e que perdem a viabilidade em poucos dias após a sua coleta. A sua conservação vem sendo estudada em termos de determinação da condição ideal de armazenamento, e tem demonstrado a importância de se conhecer o comportamento da espécie quando armazenada com diferentes teores de umidade inicial, e a umidade de equilíbrio crítica para a espécie (KANO; MÁRQUEZ & KAGEYAMA, 1978).
As levíssimas sementes aladas da espécie não necessitam de quebra de dormência. Podem apenas ser expostas ao sol por cerca de 6 horas e semeadas diretamente nos saquinhos. A quebra natural leva cerca de 3 meses e a quebra na câmara leva 9 meses. A germinação ocorre após 30 dias e de 80%.
As sementes são ortodoxas e há aproximadamente 87000 sementes em cada quilo.
Preço da Madeira no Mercado
O preço médio do metro cúbico de pranchas de ipê no Estado do Pará cotado em Julho e Agosto de 2005 foi de R$1.200,00 o preço mínimo, R$ 1509,35 o médio e R$ 2.000,00 o preço máximo (CEPEA,2005).
Blijdorp, Rotterdam, Zoo
Butterflies are part of the class of Insects in the order Lepidoptera. Moths are also included in this order. Adults butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprise the true butterflies (superfamily Papilionoidea), the skippers (superfamily Hesperioidea) and the moth-butterflies (superfamily Hedyloidea). Other families within Lepidoptera are referred to as moths. Butterfly fossils date to the mid Eocene epoch, 40–50 million years ago.[1]
Butterflies exhibit polymorphism, mimicry and aposematism. Some, like the Monarch, will migrate over long distances. Some butterflies have and parasitic relationships with organisms including protozoans, flies, ants, other invertebrates, and vertebrates. [2] [3] Some species are pests because in their larval stages they can damage domestic crops or trees; however, some species are agents of pollination of some plants, and caterpillars of a few butterflies (e.g., Harvesters) eat harmful insects. Culturally, butterflies are a popular motif in the visual and literary arts.
The Term Morph Is Inappropriate
As if we didn’t know, we asked a solitary roadside birder, “Looking for something?”
“The Gyrfalcon.”
“Have you seen it?”
“No.”
“Why isn’t anybody else looking?”
“They’re all at Grace Lake, waiting and hoping.”
Well, Maggie and I spent a little time in the parking lot overlooking Grace Lake from the southwest side. There were gulls: Herrings, Ring-bills and Lesser Black-backs, as well as some Canadas, Mallards and Common Mergs, but no falcon, just distant birders standing with their scopes on the east side of the lake.
A falcon of the tundra, one that perches on the ground or on low human-made objects, needs extensive unobstructed views, a place with wide open spaces, low-cut grass. So we went to the airport.
It was about 3:20 PM. We couldn’t ask for better timing. On the airport’s south side, we immediately drove up to a juvenile Gyrfalcon, a brown bird, perched on the snow not more than 50-60 feet from the road. Though the direction of light was almost just right, photography was not ideal. The falcon was on the other side of the airport’s chain-linked fence. Nevertheless, my camera knew what it had to do.
Seemingly indifferent to us, the Gyr was leaning over, using its beak to clean its toes, followed by facial combing with its talons. Afterwards it gazed in all directions as though seeking something, perhaps out of hunger. Then lifting its wings, it took to the air, keeping just a few feet above the ground and was quickly lost in the airport’s distant expanse of snow shadow and glare--my fourth Gyr in southeast Michigan, my ninth in the State as of today, 16 November 2019.
Alan
Tom J. Cade (1928-2019, a world renowned conservationist and co-founder of the Peregrine Fund, had this to say: “In the old literature naturalists wrote about white, grey and black ‘color phases’ of the gyrfalcon and even different species of gyrs. In fact, the different plumage types grade imperceptibly into one another, with every kind of intermediate condition represented in different individuals. . . . The Ungava region of northern Quebec is especially interesting as the whitest and blackest varieties breed together in the same area along with every kind of grey intermediate. (p. 76, The Falcons of the World, 1980).”
Eugene Potapov, assistant professor, Bryn Athyn College, is a raptor specialist and the notable author of The Gyrfalcon 2005, a definitive work: “Cade et al quite rightly state that . . . the Gyrfalcon has complete gradation rendering the term ‘morph’ inappropriate (p. 23).”
“Gyrfalcons also have shades of brown and gray in their feathers, and worn plumage may be tan-brown; Gyrs may or may not have a barred tail and moustachial stripes (p. 47).
“. . . some authors classify the birds on the basis of their background color (Cade et al. 1998). Gray form can then be a bird with gray color in the background or bird with a white background but with a lot of dark gray or brown streaks, spots or bars. The degree of the coverage of these spots can then divide the white and gray morphs. As a consequence, it is often difficult to classify Gyrs with excessive numbers or spots and a true white background ( p. 47)
“. . . Palmer (1988) considered that the division of the Gyrfalcons ‘into two or three color morphs . . . is misleading, and ‘any attempt to categorize Gyrs is subjective’, ‘because of variations from nearly (entirely?) white to almost or entirely black. Flann (2003) suggested that the Gyrfalcon has ‘continuous polymorphism’ and so does not have morphs (p.47).
“Another process is the coloration of the background, which may perhaps be independent of, but is parallel with, the variation in coloration and size of dark spots. So, . . . we have two axes of variation in coloration. One is the color as such, including both the color of the background and the color of dark spots. The second axis is the size and pattern of the dark/light spots. Interestingly, there have been no attempts to analyze this two-dimensional variation using objective criteria. In the following section we make an attempt to measure Gyrfalcon colors using a new approach (p. 47).”
To those who wish to pursue this new approach to the color patterns of the Gyrfalcon, I suggest read Potapov’s book.
As borboletas são insectos da ordem Lepidoptera classificados nas super-famílias Hesperioidea e Papilionoidea, que constituem o grupo informal Rhopalocera.
As borboletas têm dois pares de asas membranosas cobertas de escamas e peças bucais adaptadas a sucção. Distinguem-se das traças (mariposas) pelas antenas rectilíneas que terminam numa bola, pelos hábitos de vida diurnos, pela metamorfose que decorre dentro de uma crisálida rígida e pelo abdómen fino e alongado. Quando em repouso, as borboletas dobram as suas asas para cima.
As borboletas são importantes polinizadores de diversas espécies de plantas.
O ciclo de vida das borboletas engloba as seguintes etapas:
1) ovo→ fase pré-larval
2) larva→ chamada também de lagarta ou taturana,
3) pupa→ que se desenvolve dentro da crisálida (ou casulo)
4) imago→ fase adulta
_______________________
A butterfly is any of several groups of mainly day-flying insects of the order Lepidoptera, the butterflies and moths. Like other holometabolous insects, butterflies' life cycle consists of four parts, egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. Butterflies comprise the true butterflies (superfamily Papilionoidea), the skippers (superfamily Hesperioidea) and the moth-butterflies (superfamily Hedyloidea). All the many other families within the Lepidoptera are referred to as moths.
Butterflies exhibit polymorphism, mimicry and aposematism. Some, like the Monarch, will migrate over long distances. Some butterflies have evolved symbiotic and parasitic relationships with social insects such as ants. Butterflies are important economically as agents of pollination. The caterpillars of some butterflies eat harmful insects. A few species are pests because in their larval stages they can damage domestic crops or trees. Culturally, butterflies are a popular motif in the visual and literary arts.
Douze sculptures énigmatiques d'Ugo Rondinone, représentant chacune un mois de l'année, intitulées Sunrise East, sont exposées au jardin des Tuileries à Paris, dans le cadre du 38ème festival d'automne.
Ugo Rondinone est un artiste né en Suisse, en 1964, auteur d'une oeuvre polymorphe composée de vidéos, photographies, sculptures, néons,..
www.festival-automne.com/fr/programme.php?programme_id=258
voir aussi les oeuvres d'Ugo Rondinone et d'Urs Fischer présentées dans l'église San Stae pour le pavillon suisse lors de la Biennale de Venise 2007.
Aragonite from Colorado, USA. (3.4 centimeters across at its widest)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 6100 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
The carbonate minerals all contain one or more carbonate (CO3-2) anions.
Aragonite has the same chemistry as calcite - it is calcium carbonate (CaCO3). Why is it a different mineral? Aragonite has a different molecular structure - the atoms are packed differently. Different minerals having the same chemical formula are called polymorphs (another good example is graphite & diamond - both C).
The difference in atomic-level packing between calcite and aragonite can be seen at the level of mineral hand samples. Aragonite forms crystals in the orthorhombic class. Many aragonite crystals are acicular (needle-like). Many aragonites form pseudohexagonal crystals (see the above example), the result of 6 orthorhombic prisms growing parallel to each other. This specimen looks like a 6-sided crystal (hexagonal), but it's not.
Aragonite is slightly harder than calcite, at H=3.5 to 4, occurs in many colors, and easily bubbles in acid. Aragonite is a little bit heavier than calcite, due to closer packing of atoms.
Most modern seashells & coral skeletons are composed of the aragonite. Whitish-colored lime sand beaches in the world are aragonitic. Occasionally, "whitings" are seen in shallow, warm ocean environments. Whitings (cloudy, milky seawater) turn out to be loaded with tiny hair-like needles of aragonite.
In the rock record, aragonitic or aragonite-rich sediments convert to calcite over time. Cenozoic-aged carbonate sedimentary rocks are often aragonitic. Mesozoic- and Paleozoic-aged carbonates are almost always calcitic. Many ancient fossils have had their aragonitic shells dissolved away. Ancient shells that were originally calcitic are often still well preserved.
Locality: unrecorded site in Larimer County, Colorado, USA
-----------------
Photo gallery of aragonite:
This photograph shows a Sequenom chip after it has been in the nanodispenser and loaded with single nucleotide polymorphism (SNP) samples from an assay plate. The SNP genotyping system is being used to try to identify genetic factors that would increase susceptibility to rheumatoid arthritis using specimens from people with rheumatoid arthritis and specimens from controls. The principal investigator for this work was Daniel L. Kastner, M.D., Ph.D., who was the NIAMS Clinical Director and Chief of the Genetics and Genomics Branch when the photo was taken.
Photographer: Rhoda Baer
As borboletas são insectos da ordem Lepidoptera classificados nas super-famílias Hesperioidea e Papilionoidea, que constituem o grupo informal Rhopalocera.
As borboletas têm dois pares de asas membranosas cobertas de escamas e peças bucais adaptadas a sucção. Distinguem-se das traças (mariposas) pelas antenas rectilíneas que terminam numa bola, pelos hábitos de vida diurnos, pela metamorfose que decorre dentro de uma crisálida rígida e pelo abdómen fino e alongado. Quando em repouso, as borboletas dobram as suas asas para cima.
As borboletas são importantes polinizadores de diversas espécies de plantas.
O ciclo de vida das borboletas engloba as seguintes etapas:
1) ovo→ fase pré-larval
2) larva→ chamada também de lagarta ou taturana,
3) pupa→ que se desenvolve dentro da crisálida (ou casulo)
4) imago→ fase adulta
_______________________
A butterfly is any of several groups of mainly day-flying insects of the order Lepidoptera, the butterflies and moths. Like other holometabolous insects, butterflies' life cycle consists of four parts, egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. Butterflies comprise the true butterflies (superfamily Papilionoidea), the skippers (superfamily Hesperioidea) and the moth-butterflies (superfamily Hedyloidea). All the many other families within the Lepidoptera are referred to as moths.
Butterflies exhibit polymorphism, mimicry and aposematism. Some, like the Monarch, will migrate over long distances. Some butterflies have evolved symbiotic and parasitic relationships with social insects such as ants. Butterflies are important economically as agents of pollination. The caterpillars of some butterflies eat harmful insects. A few species are pests because in their larval stages they can damage domestic crops or trees. Culturally, butterflies are a popular motif in the visual and literary arts.
Anthodites in a cave in Virginia, USA.
"Cave formations" in caves are technically called speleothem. Most speleothem is composed of travertine, a crystalline-textured chemical sedimentary rock composed of calcite (CaCO3). Travertine forms in most caves and at some springs by precipitation of crystals from water. Travertine speleothem occurs in a wide variety of forms. The most common variety of travertine speleothem is dripstone, which forms by the action of dripping water. The second-most common type of travertine speleothem is flowstone, which forms by precipitation of crystals from relatively thin films of flowing water. Flowstone typically has the appearance of a frozen waterfalls.
Shown above are anthodites, a scarce variety of speleothem that was first described from this very cave - Skyline Caverns in Virginia. Anthodites are radiating clusters of quill-like to slightly vermiform structures. Individual anthodite quills are hollow. Mineral analysis by White (1994) has shown that they are composed of aragonite (CaCO3), which is a polymorph of calcite. Some have recrystallized to calcite. The anthodites of Skyline Caverns were originally in sealed chambers in a mostly-sediment filled cave passage. During tourist trail construction, workers dug out sediments and encountered small chambers having common anthodites. They were subsequently named and described in the literature in 1949. The anthodite-bearing chambers were unusual in having near-vacuum conditions. Upon opening one chamber, a worker's hat was sucked in by the low air pressure.
When pure calcium carbonate, anthodites are white-colored. The yellows and browns seen above are from iron oxides. The slightly green coloration is from algae that grows in tourist trail lighting.
Skyline Caverns is developed in structurally tilted carbonates (mixed dolostones and limestones) of the Rockdale Run Formation (Beekmantown Group, Lower Ordovician).
Locality: Skyline Caverns, Front Royal, central Warren County, northern Virginia, USA
-------------------
Reference cited:
White (1994) - The anthodites from Skyline Caverns, Virginia: the type locality. National Speleological Society Bulletin (Journal of Caves and Karst Studies) 56: 23-26.
Andalusite from the Precambrian of Russia.
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5400 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
The silicates are the most abundant and chemically complex group of minerals. All silicates have silica as the basis for their chemistry. "Silica" refers to SiO2 chemistry. The fundamental molecular unit of silica is one small silicon atom surrounded by four large oxygen atoms in the shape of a triangular pyramid - this is the silica tetrahedron - SiO4. Each oxygen atom is shared by two silicon atoms, so only half of the four oxygens "belong" to each silicon. The resulting formula for silica is thus SiO2, not SiO4.
The simplest & most abundant silicate mineral in the Earth's crust is quartz (SiO2). All other silicates have silica + impurities. Many silicates have a significant percentage of aluminum (the aluminosilicates).
Andalusite is an aluminum silicate mineral, Al2SiO5. This chemical occurs as three different polymorphs - andalusite, kyanite, and sillimanite. Andalusite is a metamorphic mineral. It has a nonmetallic luster and varies in color, but always has a white streak. It is hard (H = ~7) and has cleavage.
Chiastolite is a variety of andaulsite having dark-colored inclusions that result in a flower-like, tetraradiate structure.
Locality: unrecorded/undisclosed site in the "Keivy" area, Kola Peninsula, far-northwestern Russia
--------------------
Photo gallery of andulasite and chiastolite:
www.mindat.org/gallery.php?min=217
and
Ancient dinosaur of high-throughput genotyping, circa 2004 I suppose.
For those who might be interested, this used sequential ELISA assays, detecting haptenated terminator nucleotides in different colours (yellow and blue as I recall). It could do exactly one single nucleotide polymorphism (SNP) assay at once, and up to 25,000 samples per day (allegedly; hence, "25k"). Modern technologies can do hundreds, thousands, or even millions at once.
Practically speaking, it was fussy to use, requiring topping up of reagents if anything near that 25,000-sample mark was to be achieved, and fiddling with a lot of tubing and reagent reservoirs propped up in ice baths. It was quickly superseded by technologies capable of running many assays at once.
Still, I rather liked it at the time. I was responsible for managing delivery, installation and acceptance testing, no mean feat considering this lab was located on the 21st floor of an office block. I even ran the thing myself a couple of times.
More detail in notes on the photo, if you're really interested.
Pyrite concretions in black shale from the Pennsylvanian of Illinois, USA. (SDSMT 131, South Dakota School of Mines and Technology, Museum of Geology, Rapid City, South Dakota, USA)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5500 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
The sulfide minerals contain one or more sulfide anions (S-2). The sulfides are usually considered together with the arsenide minerals, the sulfarsenide minerals, and the telluride minerals. Many sulfides are economically significant, as they occur commonly in ores. The metals that combine with S-2 are mainly Fe, Cu, Ni, Ag, etc. Most sulfides have a metallic luster, are moderately soft, and are noticeably heavy for their size. These minerals will not form in the presence of free oxygen. Under an oxygen-rich atmosphere, sulfide minerals tend to chemically weather to various oxide and hydroxide minerals.
Pyrite is a common iron sulfide mineral (FeS2). It’s nickname is “fool's gold”. Pyrite has a metallic luster, brassy gold color (in contrast to the deep rich yellow gold color of true gold - www.flickr.com/photos/jsjgeology/sets/72157651325153769/), dark gray to black streak, is hard (H=6 to 6.5), has no cleavage, and is moderately heavy for its size. It often forms cubic crystals or pyritohedrons (crystals having pentagonal faces).
Pyrite is common in many hydrothermal veins, shales, coals, various metamorphic rocks, and massive sulfide deposits.
The pyrite specimens shown above are "pyrite suns" - discoidal concretions developed along a bedding plane in black shale (which is probably restored or reconstructed or fabricated for the retail market). Texturally, the concretions have outward-radiating crystals with moderately-developed concentricity. Mineralogically, they are principally composed of pyrite, plus minor marcasite (also FeS2 - iron sulfide; marcasite is a polymorph of pyrite).
Stratigraphy: Anna Shale (= roof shale of the Herrin Coal), upper Carbondale Formation, Desmoinesian Series, upper Middle Pennsylvanian
Locality: coal mine near Sparta, Randolph County, southwestern Illinois, USA
------------------------
Photo gallery of pyrite:
HRL2995
Cueilli à Saint-Stanislas le 20 août 2019 dans un milieu ouvert sablonneux, au pied d'un tas de gravier (calcaire)
Arrhenia peltigerina est une espèce qui parasite les lichens du genre Peltigera. On peut voir les lichens à la base des pieds du champignon sur ma photo.
Chapeau 3-9 mm.
Pied 11-20 x 0,5-1 mm, finement fibrilleux.
Spores 7-11 x 4-5,5 µm, inamyloïdes, lisses, polymorphes: oblongues, ellipsoïdes, subdacryoïdes.
Pileipellis en cutis formé d'hyphes finement incrustées ou non, bouclées.
Contexte fait d'hyphes enchevêtrées finement incrustées ou non.
Basides tétrasporiques, bouclées, 29-38 x 7-8 µm.
Cheilo- et pleurocystides absentes
Cette espèce ressemble à Arrhenia obscurata, mais cette dernière a un chapeau plus foncé, ne pousse pas sur les lichens du genre Peltigera et possède des hyphes fortement incrustées dans le pileipellis et la piléitrame.
La description de Peck (dans Kauffman) correspond parfaitement à mes spécimens. Bigelow décrit quand à lui une espèce de plus grande taille au chapeau brun foncé qui ne correspond pas vraiment à la description de Peck.
Réf. Funga Nordica.
Kauffman 1918, The gilled mushrooms (Agaricaceae) of Michigan and the Great Lakes Region.
Bigelow 1985, North American species of Clitocybe.
Laessoe et Petersen 2019, Fungi of Temperate Europe.
Andalusite from the Precambrian of Russia.
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5400 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
The silicates are the most abundant and chemically complex group of minerals. All silicates have silica as the basis for their chemistry. "Silica" refers to SiO2 chemistry. The fundamental molecular unit of silica is one small silicon atom surrounded by four large oxygen atoms in the shape of a triangular pyramid - this is the silica tetrahedron - SiO4. Each oxygen atom is shared by two silicon atoms, so only half of the four oxygens "belong" to each silicon. The resulting formula for silica is thus SiO2, not SiO4.
The simplest & most abundant silicate mineral in the Earth's crust is quartz (SiO2). All other silicates have silica + impurities. Many silicates have a significant percentage of aluminum (the aluminosilicates).
Andalusite is an aluminum silicate mineral, Al2SiO5. This chemical occurs as three different polymorphs - andalusite, kyanite, and sillimanite. Andalusite is a metamorphic mineral. It has a nonmetallic luster and varies in color, but always has a white streak. It is hard (H = ~7) and has cleavage.
Chiastolite is a variety of andaulsite having dark-colored inclusions that result in a flower-like, tetraradiate structure.
Locality: unrecorded/undisclosed site in the "Keivy" area, Kola Peninsula, far-northwestern Russia
--------------------
Photo gallery of andulasite and chiastolite:
www.mindat.org/gallery.php?min=217
and
I found several of these colorful mountain treefrogs hopping among the lichen-covered pink volcanic rocks that comprised a large talus slide. I was surprised to find this same pink/green color polymorphism displayed by the banded rock rattlesnakes and canyon treefrogs co-occurring in the same habitat.
[Camponotus Mayr 1861: 1,083+†29 spp (41.2-0.0 mya)]
Camponotus is an extremely large and complex, globally distributed genus. At present, nearly 500 sspp belonging to 45 sgg have been described and it could well be the largest ant genus of all. The enormous species richness, high levels of intraspecific and geographic variation and polymorphism render the taxonomy of Camponotus one of the most complex and difficult. Revisionary studies are generally confined to species groups and/or small geographical regions. These ants live in a variety of habitats and microhabitats and the sheer size of the genus makes any characterisation of their biology challenging. Nests are built in the ground, in rotten branches or twigs, or rarely into living wood and most spp possess a highly generalistic diet.
REFERENCES
Chairlift @ Lollapalooza 2016, Grant Park, Chicago, IL, on Saturday, July 30, 2016.
Lollapalooza 2016 Setlist:
Look Up
Polymorphing
Amanaemonesia
I Belong in Your Arms
Show U Off
Romeo
Crying In Public
Moth to the Flame
Ch-Ching
Get Real
Microscopic photo showing tumor tissue with high degree of cellularity and nuclear polymorphism. Jian-Hua Qiao, MD, FCAP, Los Angeles, CA, USA.
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As borboletas são insectos da ordem Lepidoptera classificados nas super-famílias Hesperioidea e Papilionoidea, que constituem o grupo informal Rhopalocera.
As borboletas têm dois pares de asas membranosas cobertas de escamas e peças bucais adaptadas a sucção. Distinguem-se das traças (mariposas) pelas antenas rectilíneas que terminam numa bola, pelos hábitos de vida diurnos, pela metamorfose que decorre dentro de uma crisálida rígida e pelo abdómen fino e alongado. Quando em repouso, as borboletas dobram as suas asas para cima.
As borboletas são importantes polinizadores de diversas espécies de plantas.
O ciclo de vida das borboletas engloba as seguintes etapas:
1) ovo→ fase pré-larval
2) larva→ chamada também de lagarta ou taturana,
3) pupa→ que se desenvolve dentro da crisálida (ou casulo)
4) imago→ fase adulta
_______________________
A butterfly is any of several groups of mainly day-flying insects of the order Lepidoptera, the butterflies and moths. Like other holometabolous insects, butterflies' life cycle consists of four parts, egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. Butterflies comprise the true butterflies (superfamily Papilionoidea), the skippers (superfamily Hesperioidea) and the moth-butterflies (superfamily Hedyloidea). All the many other families within the Lepidoptera are referred to as moths.
Butterflies exhibit polymorphism, mimicry and aposematism. Some, like the Monarch, will migrate over long distances. Some butterflies have evolved symbiotic and parasitic relationships with social insects such as ants. Butterflies are important economically as agents of pollination. The caterpillars of some butterflies eat harmful insects. A few species are pests because in their larval stages they can damage domestic crops or trees. Culturally, butterflies are a popular motif in the visual and literary arts.
NWA 2737
Martian Chassignite
Morocco
Found: 2000
TKW: 611 g / OBJ: Micro
NORTHWEST AFRICA 2737
‘Diderot’
Martian Chassignite
Dunite
Nine rock fragments constituting a single 611 g stone were found in the Moroccan Sahara by meteorite hunters under the organization of Bruno Fectay and Carine Bidaut. These black fragments were not recognized as meteoritic until several years later, at which time a sample was submitted for analysis. The importance of this meteorite was soon evident, and multiple analyses were conducted through a collaboration of research groups in France and elsewhere:
Laboratoire des Sciences de la Terre, (Centre National de la Recherche Scientifique—Unité Mixte de Recherche [CNRS–UMR]), École Normale Supérieure de Lyon: P. Beck, Ph. Gillet, B. Van de Moortele, B. Reynard
Université de Bretagne Occidentale, Institut Universitaire Européen de la Mer: J-A. Barrat, J. Cotten
Institut français de recherche pour l'exploitation de la mer (IFREMER), Centre de Brest (Centre national de la recherche scientifique—Unité mixte de recherche [CNRS-UMR]): M. Bohn
Planetary and Space Science Research Institute, Open University, United Kingdom: I.A. Franchi, R.C. Greenwood
Johnson Space Center, Houston, Texas
University of Tokyo, Japan
With the assigned name of NWA 2737, this olivine–chromite cumulate was classified as a dunite that exhibits many mineralogical, chemical, and petrographical similarities to the first known martian chassignite that fell in Chassigny, France in 1815. A third chassignite designated NWA 8694 (photo courtesy of L. Labenne) has been classified at the Museum National d'Histoire Naturelle, Paris, France (Hewins et al., 2014, 2015). Northwest Africa 2737 is composed of 89.6 vol% shock-blackened, cumulus forsteritic olivine, 3.1 vol% chromite, 1.6 vol% sanidine, 1.0 vol% pyroxene (augite, pigeonite, and orthopyroxene), and 0.2 vol% phosphate. Carbonates are present in both chassignites, with at least some of them showing evidence for a martian origin—shock fractures post-date the carbonate formation (Beck et al., 2006). Both chassignites have similar REE patterns, elements that are carried mostly in their apatite component. A martian origin is attested by the abundance ratio of Fe/Mn in olivine, the bulk Na/Al ratios, and by the O-isotopic ratios.
Northwest Africa 2737 is one of the least terrestrially altered martian finds as shown by its trace element composition (e.g., low Ba and Sr contents) and noble gas signatures. However, in contrast to Chassigny and the nakhlites, NWA 2737 contains trapped noble gases more similar to those in shergottites, as evidenced by the lack of martian mantle Xe, the lack of fission-derived Xe from plutonium, and the enrichment of martian atmospheric Xe (Marty et al., 2006).
While feldspars in Chassigny are mostly composed of plagioclase, with lesser amounts of labradorite and sanidine, the feldspars in NWA 2737 only occur as K-rich sanidine or Na-rich analbite. These differences could have been caused by a relatively low Al concentration in the parental melt, resulting in the delayed nucleation of plagioclase with a consequent buildup of Na in the melt (Beck et al., 2006; Papike et al., 2009). The olivine and chromite grains in both chassignites contain melt inclusions with a unique mineralogy, including the occurrence of hydrous kaersutitic (Ti-rich) amphibole, while those in NWA 2737 also include an alkali feldspar-rich glass. Six distinct melt inclusion species were described in NWA 2737 by He et al. (2010,2013) based on the diverse mineral assemblages, including olivine, orthopyroxene, augite, pigeonite, kaersutite, chlorapatite and fluorapatite, biotite, chromite, pyrrhotite, and feldspathic glass; these minerals occur in melt inclusions that span a wide range of sizes (~5–300 µm). It is thought that some melt inclusions might contain trapped parental magma at various stages of fractionation.
It was determined experimentally that the parental magma of the chassignites may have resembled a terrestrial, silica-saturated hawaiite magma with a higher than terrestrial Mg# and an aluminum content of ~12 wt% (Filiberto, 2008). It was ascertained that the chassignites likely crystallized after ~30% crystallization of mafic phases was attained.
In an effort to estimate the original magma composition of the cumulate chassignites, He et al. (2013) examined the ubiquitous, sub-mm-sized, trapped magmatic inclusions in olivine grains. In consideration of the water diffusion coefficient between amphibole and melt, as well as the extent of melt crystallization that occurred prior to amphibole formation (~45%) and other pertinent assumptions, the water content of the primary melt of NWA 2737 was calculated to be ~0.48–0.67 wt%; the water content of the primary melt of the Chassigny meteorite was previously calculated by McCubbin et al. (2010) to be 0.43–0.84 wt%. Utilizing the MELTS program with the known parameters, the research team determined that NWA 2737 was formed under pressure of ~6.8 kbar. Their deduced parental composition for NWA 2737 based on Ca:Al ratios and Mg# is quite similar to that of the martian basalt Humphrey, measured in situ by the MER rover Spirit in Gusev Crater. A broad range of Al contents has been found in martian parental source rocks—Al is relatively high in basaltic surface rocks and the chassignites, while it is thought to have been sequestered at depth in garnet in the nakhlites and most shergottites; this has implications for the magma ocean scenario of Mars' petrogenetic history.
Several differences between Chassigny and NWA 2737 have been identified by Mikouchi (2005): interstitial chromite has a larger grain size in NWA 2737, feldspar occurs as the sodic plagioclase albite in NWA 2737 rather than the calcic plagioclase anorthite, and all phases of NWA 2737 have a more magnesian composition than those in Chassigny, perhaps reflecting conditions of higher temperature and pressure during fractional crystallization from a less evolved parental melt as suggested by Nekvasil et al. (2005). Petrographic evidence indicates that NWA 2737 was the first cumulate to crystallize at the bottom of the pile, followed by Chassigny next in the sequence, while the order for NWA 8694 remains to be determined (McCubbin et al., 2013). In further studies, Mikouchi et al. (2016) found that significant ambiguities exist among the three known chassignites. For example, although each of the chassignites exhibit a similar cooling rate (0.003–0.1 °C/hr), olivine compositions between them show large variations: NWA 8694 is Fa46, Chassigny is Fa31, and NWA 2737 is Fa21; moreover, each chassignite exhibits a distinct shock history. Therefore, they suggest that each of the chassignites is more likely associated with a separate flow or lobe (possibly within a common extensive igneous unit) rather than a single sequential accumulation. See the Nakhla page for further details on the stratographic sequence for nakhlites and chassignites.
Lorand et al. (2012) studied the sulfide mineralogy and native metal assemblages in NWA 2737 and made comparisons to Chassigny. While the bulk sulfide abundance in NWA 2737 is low, troilite (and rare pentlandite) blebs up to tens of µm in size are ubiquitous at primary mineral grain contacts, and as even smaller blebs associated with chromite within melt inclusions. Although the sulfide pyrite is abundant in Chassigny, it was not identified in NWA 2737, and the Cu-sulfide chalcopyrite was virtually nonexistent; both sulfide phases were likely lost during an impact-heating event. Similarly, Fe–Os–Ir alloys that are observed in close association with troilite grains in NWA 2737 are considered to have exsolved from pyrrhotite during subsequent cooling from an impact-heating event. These differences that exist between these two chassignites can be attributed to impact-shock-related reduction processes involving high temperatures, leading to the devolatilization of S and the loss of magnetic properties.
While the overall shock effects in Chassigny are only moderate (S4), portions are present that must have experienced much higher shock pressures (45–55 GPa; S5–S6) consistent with the presence of planar deformation features and localized melting. By contrast, the olivine in NWA 2737 exhibits exceptional darkening which is thought to reflect the disordered lattice state of an incomplete transformation to olivine high pressure polymorphs, as well as the presence of nanophase FeNi-metal particles within the olivine (Reynard et al., 2006). These Fe nanoparticles are thought to have formed through subsolidus reduction of olivine during the high temperature phase (~1300°C) of a shock event corresponding to a minimum shock stage of S5. A partial cause of the darkening (brown color) in olivines as described by Treiman et al. (2006) derives from the conversion of Fe2+ to Fe3+ in an oxidizing environment, resulting from the shock heating loss of H+ that was previously dissolved in a hydrous magma. Only a low ppm abundance of Fe3+ would be required to cause the observed darkening. Continued investigations utilizing spectral reflectance techniques, including Mössbauer spectroscopy, indicate that the darkening is primarily the result of shock disseminated nanophase metallic iron particles (Pieters et al., 2007). Other deformed olivine grains in NWA 2737 have been recrystallized to a visually colorless phase. Takenouchi et al. (2015) suggested that the Fe nanoparticles were formed in association with high-pressure polymorphs such as wadsleyite during a high-pressure, high-temperature shock event. Ultimately, the wadsleyite was back-transformed to olivine during a period of high post-shock temperatures, and this olivine now appears brown due to the presence of the Fe nanoparticles. Subsequent studies were conducted by Takenouchi and Mikouchi (2016) of NWA 2737 and several shergottites that contain darkened olivine associated with shock-melt phases. They found higher Fe3+ ratios in both brown (or brownish) olivine compared to adjacent colorless olivine located within the same grain, attesting to the formation of Fe nanoparticles by olivine oxidation and reduction during transformation to high-pressure polymorphs such as ringwoodite and wadsleyite.
Cooling rate estimates for both Chassigny and NWA 2737 have been set at 28–30°C/year, consistent with a formation within a thick lava flow or a shallow dike or sill. The Sm–Nd data for both plot on a similar isochron—1.416 (±0.057) b.y. for NWA 2737, and 1.380 (±0.030) b.y. for Chassigny. Both of these chassignites, as well as the nakhlites, also have similar CRE ages of 10–11 m.y. based on 3He and 21Ne. Therefore, it may be argued that both of these chassignites, as well as the nakhlites, were ejected during a common impact event from the same igneous region on Mars. Based on Ar–Ar data, it was proposed by Bogard and Garrison (2008) that NWA 2737 may have experienced an intense impact event resulting in its burial ~1–20 m deep under a warm ejecta blanket, while a subsequent, less-intense impact event was responsible for its ejection from Mars 10–11 m.y. ago.
Differences have been noted in the gas retention ages of Chassigny and NWA 2737. After correction for terrestrial contamination, a more accurate determination of the K–Ar crystallization age for NWA 2737 was made, and this revised K–Ar age of 376 (±168) m.y. is significantly younger than that of Chassigny and the nakhlites, and more like that of shergottites (Marty et al., 2005; 2006). However, this discordant age has been attributed to the higher shock metamorphism experienced by NWA 2737
Diamond from Sierra Leone, West Africa. (public display, Carnegie Museum of Natural History, Pittsburgh, Pennsylvania, USA)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5200 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known (four of them are still unnamed). Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.
The element carbon occurs principally in its native state as graphite (C) and diamond (C). Graphite is the common & far less valuable polymorph of carbon. A scarce polymorph of carbon is diamond. The physical properties of diamond and graphite couldn’t be more different, considering they have the same chemistry. Diamond has a nonmetallic, adamantine luster, typically occurs in cubic or octahedral (double-pyramid) crystals, or subspherical to irregularly-shaped masses, and is extremely hard (H≡10). Diamonds can be almost any color, but are typically clearish, grayish, or yellowish. Many diamonds are noticeably fluorescent under black light (ultraviolet light), but the color and intensity of fluorescence varies. Some diamonds are phosphorescent - under certain conditions, they glow for a short interval on their own.
Very rarely, diamond is a rock-forming mineral (see diamondite - www.flickr.com/photos/jsjgeology/14618393527).
NWA 2737
Martian Chassignite
Morocco
Found: 2000
TKW: 611 g / OBJ: Micro
NORTHWEST AFRICA 2737
‘Diderot’
Martian Chassignite
Dunite
Nine rock fragments constituting a single 611 g stone were found in the Moroccan Sahara by meteorite hunters under the organization of Bruno Fectay and Carine Bidaut. These black fragments were not recognized as meteoritic until several years later, at which time a sample was submitted for analysis. The importance of this meteorite was soon evident, and multiple analyses were conducted through a collaboration of research groups in France and elsewhere:
Laboratoire des Sciences de la Terre, (Centre National de la Recherche Scientifique—Unité Mixte de Recherche [CNRS–UMR]), École Normale Supérieure de Lyon: P. Beck, Ph. Gillet, B. Van de Moortele, B. Reynard
Université de Bretagne Occidentale, Institut Universitaire Européen de la Mer: J-A. Barrat, J. Cotten
Institut français de recherche pour l'exploitation de la mer (IFREMER), Centre de Brest (Centre national de la recherche scientifique—Unité mixte de recherche [CNRS-UMR]): M. Bohn
Planetary and Space Science Research Institute, Open University, United Kingdom: I.A. Franchi, R.C. Greenwood
Johnson Space Center, Houston, Texas
University of Tokyo, Japan
With the assigned name of NWA 2737, this olivine–chromite cumulate was classified as a dunite that exhibits many mineralogical, chemical, and petrographical similarities to the first known martian chassignite that fell in Chassigny, France in 1815. A third chassignite designated NWA 8694 (photo courtesy of L. Labenne) has been classified at the Museum National d'Histoire Naturelle, Paris, France (Hewins et al., 2014, 2015). Northwest Africa 2737 is composed of 89.6 vol% shock-blackened, cumulus forsteritic olivine, 3.1 vol% chromite, 1.6 vol% sanidine, 1.0 vol% pyroxene (augite, pigeonite, and orthopyroxene), and 0.2 vol% phosphate. Carbonates are present in both chassignites, with at least some of them showing evidence for a martian origin—shock fractures post-date the carbonate formation (Beck et al., 2006). Both chassignites have similar REE patterns, elements that are carried mostly in their apatite component. A martian origin is attested by the abundance ratio of Fe/Mn in olivine, the bulk Na/Al ratios, and by the O-isotopic ratios.
Northwest Africa 2737 is one of the least terrestrially altered martian finds as shown by its trace element composition (e.g., low Ba and Sr contents) and noble gas signatures. However, in contrast to Chassigny and the nakhlites, NWA 2737 contains trapped noble gases more similar to those in shergottites, as evidenced by the lack of martian mantle Xe, the lack of fission-derived Xe from plutonium, and the enrichment of martian atmospheric Xe (Marty et al., 2006).
While feldspars in Chassigny are mostly composed of plagioclase, with lesser amounts of labradorite and sanidine, the feldspars in NWA 2737 only occur as K-rich sanidine or Na-rich analbite. These differences could have been caused by a relatively low Al concentration in the parental melt, resulting in the delayed nucleation of plagioclase with a consequent buildup of Na in the melt (Beck et al., 2006; Papike et al., 2009). The olivine and chromite grains in both chassignites contain melt inclusions with a unique mineralogy, including the occurrence of hydrous kaersutitic (Ti-rich) amphibole, while those in NWA 2737 also include an alkali feldspar-rich glass. Six distinct melt inclusion species were described in NWA 2737 by He et al. (2010,2013) based on the diverse mineral assemblages, including olivine, orthopyroxene, augite, pigeonite, kaersutite, chlorapatite and fluorapatite, biotite, chromite, pyrrhotite, and feldspathic glass; these minerals occur in melt inclusions that span a wide range of sizes (~5–300 µm). It is thought that some melt inclusions might contain trapped parental magma at various stages of fractionation.
It was determined experimentally that the parental magma of the chassignites may have resembled a terrestrial, silica-saturated hawaiite magma with a higher than terrestrial Mg# and an aluminum content of ~12 wt% (Filiberto, 2008). It was ascertained that the chassignites likely crystallized after ~30% crystallization of mafic phases was attained.
In an effort to estimate the original magma composition of the cumulate chassignites, He et al. (2013) examined the ubiquitous, sub-mm-sized, trapped magmatic inclusions in olivine grains. In consideration of the water diffusion coefficient between amphibole and melt, as well as the extent of melt crystallization that occurred prior to amphibole formation (~45%) and other pertinent assumptions, the water content of the primary melt of NWA 2737 was calculated to be ~0.48–0.67 wt%; the water content of the primary melt of the Chassigny meteorite was previously calculated by McCubbin et al. (2010) to be 0.43–0.84 wt%. Utilizing the MELTS program with the known parameters, the research team determined that NWA 2737 was formed under pressure of ~6.8 kbar. Their deduced parental composition for NWA 2737 based on Ca:Al ratios and Mg# is quite similar to that of the martian basalt Humphrey, measured in situ by the MER rover Spirit in Gusev Crater. A broad range of Al contents has been found in martian parental source rocks—Al is relatively high in basaltic surface rocks and the chassignites, while it is thought to have been sequestered at depth in garnet in the nakhlites and most shergottites; this has implications for the magma ocean scenario of Mars' petrogenetic history.
Several differences between Chassigny and NWA 2737 have been identified by Mikouchi (2005): interstitial chromite has a larger grain size in NWA 2737, feldspar occurs as the sodic plagioclase albite in NWA 2737 rather than the calcic plagioclase anorthite, and all phases of NWA 2737 have a more magnesian composition than those in Chassigny, perhaps reflecting conditions of higher temperature and pressure during fractional crystallization from a less evolved parental melt as suggested by Nekvasil et al. (2005). Petrographic evidence indicates that NWA 2737 was the first cumulate to crystallize at the bottom of the pile, followed by Chassigny next in the sequence, while the order for NWA 8694 remains to be determined (McCubbin et al., 2013). In further studies, Mikouchi et al. (2016) found that significant ambiguities exist among the three known chassignites. For example, although each of the chassignites exhibit a similar cooling rate (0.003–0.1 °C/hr), olivine compositions between them show large variations: NWA 8694 is Fa46, Chassigny is Fa31, and NWA 2737 is Fa21; moreover, each chassignite exhibits a distinct shock history. Therefore, they suggest that each of the chassignites is more likely associated with a separate flow or lobe (possibly within a common extensive igneous unit) rather than a single sequential accumulation. See the Nakhla page for further details on the stratographic sequence for nakhlites and chassignites.
Lorand et al. (2012) studied the sulfide mineralogy and native metal assemblages in NWA 2737 and made comparisons to Chassigny. While the bulk sulfide abundance in NWA 2737 is low, troilite (and rare pentlandite) blebs up to tens of µm in size are ubiquitous at primary mineral grain contacts, and as even smaller blebs associated with chromite within melt inclusions. Although the sulfide pyrite is abundant in Chassigny, it was not identified in NWA 2737, and the Cu-sulfide chalcopyrite was virtually nonexistent; both sulfide phases were likely lost during an impact-heating event. Similarly, Fe–Os–Ir alloys that are observed in close association with troilite grains in NWA 2737 are considered to have exsolved from pyrrhotite during subsequent cooling from an impact-heating event. These differences that exist between these two chassignites can be attributed to impact-shock-related reduction processes involving high temperatures, leading to the devolatilization of S and the loss of magnetic properties.
While the overall shock effects in Chassigny are only moderate (S4), portions are present that must have experienced much higher shock pressures (45–55 GPa; S5–S6) consistent with the presence of planar deformation features and localized melting. By contrast, the olivine in NWA 2737 exhibits exceptional darkening which is thought to reflect the disordered lattice state of an incomplete transformation to olivine high pressure polymorphs, as well as the presence of nanophase FeNi-metal particles within the olivine (Reynard et al., 2006). These Fe nanoparticles are thought to have formed through subsolidus reduction of olivine during the high temperature phase (~1300°C) of a shock event corresponding to a minimum shock stage of S5. A partial cause of the darkening (brown color) in olivines as described by Treiman et al. (2006) derives from the conversion of Fe2+ to Fe3+ in an oxidizing environment, resulting from the shock heating loss of H+ that was previously dissolved in a hydrous magma. Only a low ppm abundance of Fe3+ would be required to cause the observed darkening. Continued investigations utilizing spectral reflectance techniques, including Mössbauer spectroscopy, indicate that the darkening is primarily the result of shock disseminated nanophase metallic iron particles (Pieters et al., 2007). Other deformed olivine grains in NWA 2737 have been recrystallized to a visually colorless phase. Takenouchi et al. (2015) suggested that the Fe nanoparticles were formed in association with high-pressure polymorphs such as wadsleyite during a high-pressure, high-temperature shock event. Ultimately, the wadsleyite was back-transformed to olivine during a period of high post-shock temperatures, and this olivine now appears brown due to the presence of the Fe nanoparticles. Subsequent studies were conducted by Takenouchi and Mikouchi (2016) of NWA 2737 and several shergottites that contain darkened olivine associated with shock-melt phases. They found higher Fe3+ ratios in both brown (or brownish) olivine compared to adjacent colorless olivine located within the same grain, attesting to the formation of Fe nanoparticles by olivine oxidation and reduction during transformation to high-pressure polymorphs such as ringwoodite and wadsleyite.
Cooling rate estimates for both Chassigny and NWA 2737 have been set at 28–30°C/year, consistent with a formation within a thick lava flow or a shallow dike or sill. The Sm–Nd data for both plot on a similar isochron—1.416 (±0.057) b.y. for NWA 2737, and 1.380 (±0.030) b.y. for Chassigny. Both of these chassignites, as well as the nakhlites, also have similar CRE ages of 10–11 m.y. based on 3He and 21Ne. Therefore, it may be argued that both of these chassignites, as well as the nakhlites, were ejected during a common impact event from the same igneous region on Mars. Based on Ar–Ar data, it was proposed by Bogard and Garrison (2008) that NWA 2737 may have experienced an intense impact event resulting in its burial ~1–20 m deep under a warm ejecta blanket, while a subsequent, less-intense impact event was responsible for its ejection from Mars 10–11 m.y. ago.
Differences have been noted in the gas retention ages of Chassigny and NWA 2737. After correction for terrestrial contamination, a more accurate determination of the K–Ar crystallization age for NWA 2737 was made, and this revised K–Ar age of 376 (±168) m.y. is significantly younger than that of Chassigny and the nakhlites, and more like that of shergottites (Marty et al., 2005; 2006). However, this discordant age has been attributed to the higher shock metamorphism experienced by NWA 2737
Diamonds from Russia (probably Siberia). (crystals are ~0.7 to 0.9 millimeters in size)
A mineral is a naturally-occurring, solid, inorganic, crystalline substance having a fairly definite chemical composition and having fairly definite physical properties. At its simplest, a mineral is a naturally-occurring solid chemical. Currently, there are over 5900 named and described minerals - about 200 of them are common and about 20 of them are very common. Mineral classification is based on anion chemistry. Major categories of minerals are: elements, sulfides, oxides, halides, carbonates, sulfates, phosphates, and silicates.
Elements are fundamental substances of matter - matter that is composed of the same types of atoms. At present, 118 elements are known. Of these, 98 occur naturally on Earth (hydrogen to californium). Most of these occur in rocks & minerals, although some occur in very small, trace amounts. Only some elements occur in their native elemental state as minerals.
To find a native element in nature, it must be relatively non-reactive and there must be some concentration process. Metallic, semimetallic (metalloid), and nonmetallic elements are known in their native state.
The element carbon occurs principally in its native state as graphite (C) and diamond (C). Graphite is the common & far less valuable polymorph of carbon. A scarce polymorph of carbon is diamond. The physical properties of diamond and graphite couldn’t be more different, considering they have the same chemistry. Diamond has a nonmetallic, adamantine luster, typically occurs in cubic or octahedral (double-pyramid) crystals, or subspherical to irregularly-shaped masses, and is extremely hard (H≡10). Diamonds can be almost any color, but are typically clearish, grayish, or yellowish. Many diamonds are noticeably fluorescent under black light (ultraviolet light), but the color and intensity of fluorescence varies. Some diamonds are phosphorescent - under certain conditions, they glow for a short interval on their own.
Very rarely, diamond is a rock-forming mineral (see diamondite - www.flickr.com/photos/jsjgeology/14618393527).