Amethyst
Image: Aagnverglaser (CC BY-SA 4.0)
Mineral NameAmethyst
Chemical FormulaSiO2
Mohs Hardness7.5
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.65
Colorspurple, violet
Transparencytransparent
Type LocalityBrazil
Mineral GroupSilicates
Usesjewelry, collector, decorative objects
Associated Mineralsquartz, calcite, feldspar, goethite
Raritycommon
Description
Amethyst is a popular purple variety of quartz, often found as crystalline linings within geodes or in veins. Its color ranges from pale lilac to deep violet.
Geological Context
Amethyst forms in hydrothermal veins and cavities, particularly in volcanic rocks, where silica-rich fluids deposit quartz crystals. The purple color is due to iron impurities and natural irradiation.
