Anatase on Smoky Quartz
Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
Mineral NameAnatase on Smoky Quartz
Chemical FormulaTiO₂ (Anatase), SiO₂ (Smoky Quartz)
Mohs Hardness5.5
Streak ColorWhite
CleavagePerfect in two directions (Anatase), None (Smoky Quartz)
FractureConchoidal (Smoky Quartz), Subconchoidal to irregular (Anatase)
Specific Gravity2.65
Colorsblack, smoky brown, grey
TransparencyTransparent to translucent
Type LocalitySwitzerland
Mineral GroupOxides (Anatase), Silicates (Smoky Quartz)
Usescollector, jewelry, minor industrial (titanium source)
Associated Mineralsquartz, feldspar, chlorite, adularia, rutile
Description
A specimen featuring small, lustrous black anatase crystals scattered across a large, translucent smoky brown quartz crystal, partially covered by an earthy matrix.
Geological Context
Anatase and smoky quartz commonly form together in alpine clefts and hydrothermal veins within igneous and metamorphic rocks. The smoky color in quartz is due to natural irradiation of aluminum impurities.
