Amethyst
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 NameAmethyst
Chemical FormulaSiO2
Mohs Hardness7
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.65
Colorspurple, violet, white, grey
Transparencytransparent
Type LocalityIdar-Oberstein, Hunsrück Mts, Rhineland-Palatinate, Germany
Mineral GroupSilicates
Usesjewelry, collector's item, ornamental
Associated Mineralschalcedony, agate, calcite
Raritycommon
Description
A geode-like specimen displaying a cavity lined with numerous sparkling purple amethyst crystals, set within a greyish-white host rock.
Geological Context
Amethyst typically forms in hydrothermal solutions within volcanic rocks, such as basalt flows, where silica-rich fluids deposit quartz in vugs and geodes, with its characteristic purple color resulting from iron impurities and natural irradiation.
