Agate
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Bracelet Chalcedony Stone Fashion Jewelry via t.co/0KHID6AwTR #rings #pendants #earrings #bangles #necklace t.co/uR8sfSC04S (via Twitter twitter.com/ibeautifulart/status/768373089738510337)
Nodule of agate found on a Cody 59ers Rock club field trip on private land in Montana. Thanks to the ranchers for giving us permission.
Pockets of botryoidal nodules of chalcedony that have been stained by iron and manganese oxides lie in erosional ‘pockets’ within Paton’s Hole near Leavitt Reservoir in Big Horn County Wyoming. When cut these nodules are gray to white inside and have faint banding. The colorful hills in the “Hole” and around it are made up of beds of the Cretaceous Cloverly Formation. The Sykes Mountain Member or “Rusty Beds” lie at the top of the Cloverly Formation. The gray hills on the horizon are the Cretaceous Thermopolis, Mowry and Frontier Formations which are composed mostly of shale with some sandstone interbeds. Currently the reservoir has been drained and a new dam is planned. This area may be partially inundated when the lake is refilled behind the new dam.
Silica rich water containing tiny amounts of dissolved minerals are deposited at high temperatures and pressures deep underground over millions of years in order to create the pretty banding in this chalcedony pebble.
Photo taken for the 'Looking close... on Friday!' theme 'a single stone'.
Chalcedony is a microcrystalline variety of quartz which can appear translucent to opaque. It is often grey in appearance but impurities make it look blue, lavender or yellow. It is often used for making jewellery.
Chalcedony’s healing properties include removing negative energies, facilitating thoughtful communication and reducing anxiety.
My recently acquired and rather splendid Carnelian pyramid. It's the largest pyramid I've bought, 6cm square at the base, 7 cm high and weighing 218 grams.
Carnelian is a glassy, translucent stone, an orange-colored variety of Chalcedony, a mineral of the Quartz family.
Carnelian restores vitality and motivation, and stimulates creativity. It gives courage, promotes positive life choices, dispels apathy and motivates for success. Carnelian is useful for overcoming abuse of any kind. It helps in trusting yourself and your perceptions.
Definitely Dreaming 'beginning with C', 10/52
120 pictures in 2020 (89) pyramid
This specimen measures 32x32x22 mm. The photo is a composite of 17 photographs combined using Helicon Focus DOF stacking software.
rock of chalcedony
in a mind of lumpen thought
a levee of illumined rock was wrought
limned with herbs of winter’s green
it would repel the hordes of proles unseen
but spoil befell the brittle chalcedony
the onyx wall usurped by misanthropy
(from: Ditties and Doggerels by FF Whitamore)
This specimen of Quartz, variety chalcedony and agate, was found in the Lysite agate beds in the Bridger Mountains north of Lysite, in Fremont County, Wyoming. Botryoidal chalcedony on banded agate is common in these beds.
Chalcedony and agate are cryptocrystalline (microscopic to submicroscopic) varieties of quartz. Most chalcedony and agate contains small amounts (1%-20%) of the silica mineral mogánite which has the same chemical formula as quartz (SiO₂) with some water and a different crystalline structure. With time the mogánite slowly converts into quartz. This conversion process results in mogánite-free chalcedony/agate.
The colors of this necklace reminds me of the soothing waters of Magen's Bay in St. Thomas, Virgins Island.
My husband and I vacationed there when I was pregnant with our first daughter! AHHH the life we had there! It was so relaxing and serene that that calmness still carries with me (especially since my life is chaotic with 3 crazy girls!)
This is a new variation ot my Eliza necklace. This one has Neon blue apatite rondelles, Peruvian Chalcedony, and Mystic Blue Quartz. I especially love the assymetrical vermeil charm on the side.
A huge (25 x 15 mm), silky smooth beautiful blue chalcedony briolette secured inside a 14k GF teardrop frame which has a fringe of faceted aqua tone apatite brios. A little cluster of bronze keishi petal pearls adorn the top of the teardrop and a cluster of neon blue apatite rondells connect the pendant to a 14k goldfilled chain which is dotted with more apatite and a few shaded prehnite rondells.....
This quartz, var. chalcedony, "geode" was found along a small drainage off of the North Fork of the Shoshone River in the Absaroka Mountains west of Cody, Wyoming. The specimen was backlit with a small flashlight.
Chalcedony is a cryptocrystalline (microscopic to submicroscopic) variety of quartz. Most chalcedony contains small amounts (1%-20%) of the silica mineral Mogánite which has the same chemical formula as quartz (SiO₂) with some water and a different crystalline structure. With time the mogánite slowly converts into quartz. This conversion process results in mogánite-free chalcedony.
References:
Donated by a member of the Northeast Wyoming Rockhounds, this petrified wood was collected in the Powder River near the Montana border. Its age is undetermined because it was not found in situ.
Petrified wood forms when fallen trees are rapidly buried by sediment—such as volcanic ash or river silt—that cuts off oxygen and slows decay. Over millions of years, mineral-rich groundwater seeps through the buried wood.
During permineralization, the dissolved minerals fill the tiny pores and spaces within the wood. If mineralization continues, replacement occurs—where the original cellular material is gradually replaced, atom by atom, with minerals such as quartz, chalcedony, or jasper. Both processes often occur together, though sometimes mineralization stops at the permineralization stage.
Over time, silica-rich fluids deposited quartz (SiO₂) in forms such as agate, chalcedony, or jasper, preserving the wood’s structure and growth patterns in beautiful detail. Occasionally, other minerals such as calcite, pyrite, opal, or hematite may serve as the permineralizing material. In some cases, even uranium ores—notably uraninite and carnotite—can fill the pore spaces, giving the fossil distinctive coloration and added scientific interest.
Paleontologists prefer terms like permineralization and replacement over petrifaction because they accurately describe the processes involved. Not all fossils form this way—others may result from carbonization, molds and casts, preservation in amber or tar, or natural mummification.
Specimen WY-2025-17-01
Crystals are so interesting, this one looks like it is polished but it is not. This is natural.
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Mixed tumbled chalcedony / agate assortment (polished gemstone pebbles).
Most stones in the image are agate or chalcedony, both forms of microcrystalline quartz (SiO₂). They have been cut and tumble-polished to produce smooth rounded shapes used for jewelry, decorative bowls, or lapidary collections.
Key indicators visible in the photo:
Translucent body with light passing through many pieces
High polish with rounded edges (typical of tumbling)
Banding and internal structures in several stones
Wide color range (red, orange, yellow, green, blue, purple, clear)
Agate and chalcedony can appear in many colors depending on trace mineral impurities.
Likely Varieties Present
Because these are mixed stones, several chalcedony types appear in the pile:
Carnelian agate – red to orange translucent stones
Yellow chalcedony / agate – honey-yellow pieces
Green chalcedony – apple-green translucent stones
Purple chalcedony – lavender-colored pieces
Clear chalcedony / quartz – colorless translucent stones
Banded agate – pieces showing curved or layered stripes
Agate is typically defined as translucent chalcedony with banding, while jasper is the opaque equivalent.
Description
A dense pile of polished gemstone pebbles photographed under bright transmitted light. The stones are smooth and rounded with glossy surfaces, showing internal bands, inclusions, and color gradients typical of agate and chalcedony. Colors range from vivid reds and oranges to pale yellows, greens, blues, purples, and transparent whites. Several stones display layered banding or dendritic inclusions, indicating natural silica deposition during formation.
Elongated teardrop chalcedony in a very subtle pastel green topped with blue topaz, spinel rondelles with tints of yellow and orange. a 30mm drop from earwire. Made using 925 silver wires and earwire.
Called by some locals, rockhounds and lapidarists Medicine Bow agate, this white chalcedony is full of dendrites of manganese oxides that were incorporated into the material during formation. As the name suggests, the chalcedony comes from an area northeast of Medicine Bow and west of the Laramie Range in Albany County, Wyoming. It is also called black plume agate, Medicine Bow plume agate, Marshall agate (for a nearby place) and white moss agate. This sample is approximately 6” across and 3” high.
Depending on the context, the term "chalcedony" has different meanings. Some apply the term to all varieties of quartz that are made of microscopic or submicroscopic crystals. Some geologists refer to these varieties of quartz as cryptocrystalline quartz. Examples are the different types of agate, jasper, flint; chert, chrysoprase, onyx, pietersite, etc. An agate is a very translucent and often banded form of chalcedony. The Medicine Bow agate does not fit this definition so some would say it is not a true agate.
The name, chalcedony, can also used in more restrictive ways by both mineralogists and rockhounds. There is not enough space to discuss those definitions in this caption but if the definition given above doesn’t fit your view of what chalcedony is, one of the others probably will. A good resource for a discussion on the different uses of the term chalcedony is: www.mindat.org/min-960.html#anchortopapproximately
Botryoidal chalcedony development inside a cavity.
Likely formed from silica-rich fluids precipitating layer by layer.
Gel phase textures still visible in the structure.
Geological slow art at its finest.
A good size Blue Chalcedony stone set in a ring.
Calcedony is a mineral in the Quartz family. This is a dark blue one with lots of lights in it as well as milky areas .Some of them very solid that looks like clouds.
Captured with iPhone and Olloclip Macro Lens. Edited in In Snapseed.
These beautiful silicon creatures live in only one place on the planet. in Marocco. According to their structure, these are quartz druses of crystals and chalcedony. Both are silicon oxide (Si O2). Some attribute them to the Gobi Agate, but this is not correct. Other equally beautiful silicon creatures live in the Gobi Desert, but not Panda Agates.
This mineral also known as Truffle Chalcedony, Womb Stone, Chalcedony Nodules.
These are living organisms of silicon life form. This form of life appeared on our planet before water-carbon. They live, feed and grow, multiply, can get sick and die. The silicon world has its own parasites and food chains, and they also differ in the complexity of their structure and defrosting.
The diversity of silicon life is very large, but not as great as the water-carbon life form we are used to. In addition, the silicon life form exists in a different time corridor. For us, they are motionless, therefore they do not seem alive to us. Scientists disagree about longevity. Some scientists suggest that Agates, for example, live for hundreds of thousands of years, some for hundreds of millions.
I am very closely engaged in the study of this issue and will soon acquaint you with my discoveries.
"Carbon chauvinism"
This term is a consequence of the assumption that everything that can be called living must be built primarily from carbon. It is clear that this form of life is closest to us, so it is extremely difficult for us to imagine a different biochemistry.
The author of the term, astrophysicist Carl Sagan, criticizing this point of view, suggested that the basis for its nomination is only the fact that its adherents themselves consist of carbon and water and absorb oxygen in the process of metabolism.
A tightly grouped arrangement of polished tumbled minerals and semiprecious stones photographed against a bright white background. The stones vary widely in color, translucency, and internal structure, creating a layered composition of reds, pinks, greens, blues, violets, creams, and honey tones. Many are semi-transparent, allowing light to penetrate and reveal fractures, inclusions, bubbles, and internal veils.
Several stones appear identifiable:
* Purple translucent stone at right: likely amethyst quartz.
* Deep blue stone in foreground: possibly sodalite rather than lapis, due to the white veining and absence of pyrite flecks.
* Pale pink transparent stones: likely rose quartz.
* Green stones: probably green aventurine.
* Honey/orange translucent stones: possibly chalcedony, carnelian, or agate.
* Milky gray stone with blue specks: could be dendritic or included chalcedony/opalite.
* Clear fractured stone in front: likely quartz crystal with internal cracking.
* Dark red granular stone at left foreground: possibly red jasper or garnet-bearing material.
The polished surfaces reflect the light source strongly. Window-grid reflections are visible across many stones, giving clues about the lighting setup and emphasizing their gloss and curvature.
Discussion
This image works well because of the contrast between:
* opaque vs translucent materials
* saturated vs pastel colors
* smooth surfaces vs internally fractured textures
The arrangement feels organic rather than strictly geometric. Stones overlap naturally, creating depth without becoming visually chaotic.
Technically:
* The exposure is controlled well enough to retain detail inside translucent stones without blowing highlights excessively.
* Depth of field appears moderate to deep, likely from focus stacking or a relatively small aperture.
* White background is slightly warm rather than pure neutral white, which helps the minerals feel less clinical.
The reflections are important compositional elements here. Rather than eliminating them completely, they help communicate polish, curvature, and transparency. For mineral photography, completely reflection-free lighting can sometimes make stones appear flat or plastic.
A few stones appear to contain:
* internal fractures (“feathers”)
* mineral inclusions
* possible dye enhancement in the bright red specimen
* trapped bubble-like structures in some chalcedony-like pieces
The bright red stone especially looks unusually saturated for a natural tumbled stone and may be dyed agate or synthetic glass.
Agate ("Dryhead Agate") from Wyoming, USA. (public display, Gorman Nature Center, Mansfield, Ohio, USA)
"Agate" is a rockhound/collector term for cavities in rocks (usually sedimentary rocks such as limestone or igneous rocks such as basalt) that have been partially or completely filled with irregularly concentric layers of microcrystalline, fibrous quartz (chalcedony - SiO2). Agate is quartz.
"Dryhead Agate" comes from southern Montana, but this specimen is attributed to Wyoming.
Gorgeous elongated teardrops of pale blue chalecodony are wrapped in tons of sterling silver wire to make this elegant pair of earrings.
These are polished lapidary stones/cabochons, and the set appears to be chosen for strong graphic pattern rather than being from one mineral family.
Identification
1) Upper left — green and black stone
Most likely: Serpentine / serpentine-rich rock
Alternative possibilities: green marble, ophicalcite, nephrite-like decorative stone
Why: strong apple-to-olive green body color with irregular black patches and a waxy to slightly granular appearance.
Description:
A rectangular polished stone with mottled green ground and dark black-green inclusions. It has a bold, camouflage-like pattern and a somewhat organic, metamorphic look.
Confidence: Moderate
2) Upper right — pale translucent stone with branching inclusions
Most likely: Dendritic agate or moss agate
Alternative possibilities: plume agate, chalcedony with manganese/iron dendrites
Why: translucent chalcedony body with fine branching, fern-like blue-green inclusions.
Description:
An elongated teardrop-shaped polished stone, semi-translucent gray to milky beige, marked by delicate branching inclusions that resemble algae, roots, or frost patterns. This is the most “landscape-like” stone in the group.
Confidence: High
3) Lower left — orange, beige, and gray brecciated stone
Most likely: Brecciated jasper
Alternative possibilities: fancy jasper, rhyolite, agatized breccia
Why: angular fractured zones, orange-red jasper-like fields, and silica-filled seams suggest a brecciated decorative stone.
Description:
A polished freeform stone with vivid orange sections broken by dark fracture lines and bordered by beige-gray agate-like material. The pattern looks cracked, repaired, and geologic, with strong contrast between opaque and translucent areas.
Confidence: Moderate to high
4) Lower right — black and white banded stone
Most likely: Zebra jasper
Alternative possibilities: zebra marble, banded calcite, striped onyx-marble sold commercially as “zebra stone”
Why: bold black-and-white striping with opaque body and decorative-stone appearance.
Description:
A rectangular rounded polished stone with dramatic vertical black and white bands. The pattern is bold, graphic, and high contrast, resembling brushstrokes or animal striping.
Confidence: Moderate
Overall description
This is a visually coordinated set of polished stones with four distinct pattern types:
mottled green-black
dendritic translucent
brecciated orange-gray
striped black-white
They work well together because each shows a different natural pattern language: mottling, branching, fracturing, and banding.
Continuing a dynasty can be much harder than starting one. The successors of Augustus, the first Roman emperor, worked hard to demonstrate their connection to Augustus and hence their right to rule. Antonia Minor, shown here in this large cameo, was Augustus's niece and the mother of possible heirs to the throne.
The cameo depicts Antonia wearing a veil and a diadem in the guise of a priestess of the cult of the deified Augustus. Stars and a portrait of Augustus wearing a laurel wreath decorate the diadem. The cameo was probably carved after Antonia's death in A.D. 37, during the reign of her son Claudius, the fourth Roman emperor.
Small-scale portraits carved in the round from precious stones were probably once set into statues made of gold or silver, although no complete examples survive today. Elaborate cameo carvings such as this one were part of the production of commemorative luxury goods at the Roman imperial court.
Roman, white chalcedony, ca. 41-54 CE
Getty Villa Museum (81.AN.101)
The image appears to show four translucent mineral or glass specimens arranged against a black reflective background. Identification confidence varies by piece because several materials can look similar when polished or fractured.
Most likely identifications
Large rough clear piece (top)
Most likely: quartz (Silicon dioxide, SiO₂) or possibly clear glass slag.
* Rough fractured texture without obvious crystal termination.
* Internally heavily fractured with conchoidal-looking breaks.
* Slight cloudy inclusions and iron-stained specks.
* If it is quartz, it would be rock crystal quartz.
* If it feels unusually light or shows rounded melt-like surfaces, it could instead be industrial glass.
Confidence: Moderate.
Tumbled clear stone (left center)
Most likely: clear quartz (rock crystal quartz).
* Water-clear appearance with internal fractures and inclusions.
* Rounded, polished/tumbled finish.
* Warm yellow-orange internal reflections likely come from lighting/background reflections rather than mineral color.
Confidence: Fairly high.
Pink translucent sphere (right center)
Most likely: rose quartz sphere.
* Soft pink coloration.
* Semi-translucent body with cloudy internal veils.
* Commonly carved into spheres exactly like this.
* Internal fracture reflections are typical for quartz.
Alternative:
* Dyed glass or synthetic material is possible if color is unnaturally even.
Confidence: Moderate to high.
Purple polished oval (bottom)
Most likely: purple chalcedony/agate or dyed quartz/glass.
* Strong saturated violet-purple coloration.
* Very smooth polished cabochon-like surface.
* More translucent at edges.
* The color intensity raises suspicion of dye treatment or glass.
Natural possibilities:
* Purple chalcedony.
* Amethyst with very dense polish.
* Dyed agate.
Confidence: Low to moderate.
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Visual characteristics
The composition works because of:
* Contrast between rough and polished surfaces.
* Progression from colorless → pink → purple.
* Strong specular highlights emphasizing transparency.
* Black reflective background isolating the forms.
The lighting appears highly diffused but directional enough to preserve internal reflections and fracture detail. The purple stone especially shows a large softbox/grid reflection.
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Geological notes
Quartz family
Quartz varieties can appear:
* Clear: rock crystal.
* Pink: rose quartz.
* Purple: amethyst.
They all share:
* Hardness: 7 Mohs.
* Glassy luster.
* Conchoidal fracture.
* Transparency ranging from opaque to clear.
Glass possibility
Some pieces may instead be:
* Decorative tumbled glass.
* Furnace slag glass.
* Synthetic crystal.
Indicators of glass:
* Rounded internal bubbles.
* Flow structures.
* Extremely uniform color.
* Softer edges after polishing.
Chalcedony with Colloidal Cinnabar. Cinnabar is mercury sulfide, the primary ore of the metal. The host rock for mecury deposits at this site is a highly silicified rhyolite tuff, originally deposited as an ash fall in a lake within a collapsed caldera. The cinnabar in this deposit is characterized by trace amounts of chlorine which cause the bright red mineral to turn black very quickly after exposure to light, often within hours. In this freshly uncovered nodule, the cinnabar that previously had been exposed at the surface has already turned black. McDermitt Mine. Opalite District. Near McDermitt, Humboldt Co., Nevada.