Natrolite Needles
The card alongside this exhibit described the item as delicate needles with apophyllite on basalt. Natrolite is a tectosilicate mineral species belonging to the zeolite group. It is a hydrated sodium and aluminium silicate with the formula Na2Al2Si3O10 • 2H2O. For me, the delicacy of all those hair-like crystals is amazing.
It was named natrolite by Martin Heinrich Klaproth in 1803, derived from natron, the Greek word for soda, in reference to the sodium content and lithos, meaning stone. Needle stone or needle-zeolite are other informal names, alluding to the common acicular habit of the crystals, which are often very slender and are aggregated in divergent tufts as above.
Klaproth is an interesting character. A German chemist of the 18th-19th centuries, he discovered uranium (1789), zirconium (1789), and cerium (1803), and named titanium (1795) and tellurium (1798)! Busy guy...
Natrolite can come in a variety colours: white, colourless, red, yellow, brown, green or bluish. Apophyllite is a group of phyllosilicates and like natrolite is typically found associated with basalt.
Seen under glass in the Minerals section of the Natural History Museum in South Kensington, London, the item's long axis is about 15cm. The card describes it as coming from Neubauerberg, Bohemia. However, Google and Google Earth don't recognise that. Further digging on more specialised websites lead you to a hill called Neubauer Berg bei Mückenhan. It's an old German name for what is today known as Puchavec hill, near to the village of Provodin in the Czech Republic's Ceská Lipa district.
Can anyone describe how such a delicate-appearing item might be extracted from the surrounding rock in days gone by without destroying it? I would think my old hammer and chisel method might ruin it long before it was removable, but were other methods available?
Natrolite Needles
The card alongside this exhibit described the item as delicate needles with apophyllite on basalt. Natrolite is a tectosilicate mineral species belonging to the zeolite group. It is a hydrated sodium and aluminium silicate with the formula Na2Al2Si3O10 • 2H2O. For me, the delicacy of all those hair-like crystals is amazing.
It was named natrolite by Martin Heinrich Klaproth in 1803, derived from natron, the Greek word for soda, in reference to the sodium content and lithos, meaning stone. Needle stone or needle-zeolite are other informal names, alluding to the common acicular habit of the crystals, which are often very slender and are aggregated in divergent tufts as above.
Klaproth is an interesting character. A German chemist of the 18th-19th centuries, he discovered uranium (1789), zirconium (1789), and cerium (1803), and named titanium (1795) and tellurium (1798)! Busy guy...
Natrolite can come in a variety colours: white, colourless, red, yellow, brown, green or bluish. Apophyllite is a group of phyllosilicates and like natrolite is typically found associated with basalt.
Seen under glass in the Minerals section of the Natural History Museum in South Kensington, London, the item's long axis is about 15cm. The card describes it as coming from Neubauerberg, Bohemia. However, Google and Google Earth don't recognise that. Further digging on more specialised websites lead you to a hill called Neubauer Berg bei Mückenhan. It's an old German name for what is today known as Puchavec hill, near to the village of Provodin in the Czech Republic's Ceská Lipa district.
Can anyone describe how such a delicate-appearing item might be extracted from the surrounding rock in days gone by without destroying it? I would think my old hammer and chisel method might ruin it long before it was removable, but were other methods available?