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Prasiolite (also known as green quartz, green amethyst or vermarine) is a green variety of quartz. Since 1950, almost all natural prasiolite has come from a small Brazilian mine, [citation needed] but it has also been mined in the Lower Silesia region of Poland. Naturally occurring prasiolite has also been found in the Thunder Bay area of ...
A silicate mineral is generally an inorganic compound consisting of subunits with the formula [SiO 2+n] 2n−.Although depicted as such, the description of silicates as anions is a simplification.
Jet is found in two forms, hard and soft. [5] Hard jet is the result of carbon compression and salt water; soft jet may be the result of carbon compression and fresh water. [5] Despite the name they both occupy the same area of the Mohs scale with the difference being that soft jet is more likely to crack when exposed to changes in temperature. [6]
Quartz is, therefore, classified structurally as a framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. [10] Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation ...
Due to the thermal stability and composition, it is used in 5D optical data storage [12] and in semiconductor fabrication furnaces. [13] [14] Fused quartz has nearly ideal properties for fabricating first surface mirrors such as those used in telescopes. The material behaves in a predictable way and allows the optical fabricator to put a very ...
This property is used to grow single crystals of quartz in a hydrothermal process where natural quartz is dissolved in superheated water in a pressure vessel that is cooler at the top. Crystals of 0.5–1 kg can be grown for 1–2 months. [12] These crystals are a source of very pure quartz for use in electronic applications. [15]
Quartz is commonly the dominant mineral component, and some mica is often present. Apart from the mineral content, rock fragments may also be a significant component. Arkose usually contains small amounts of calcite cement, which causes it to effervesce (fizz) slightly in dilute hydrochloric acid; sometimes the cement also contains iron oxide.
Mohs hardness kit, containing one specimen of each mineral on the ten-point hardness scale. The Mohs scale (/ m oʊ z / MOHZ) of mineral hardness is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of minerals through the ability of harder material to scratch softer material.