Amethyst
Image: Фотостудия Современник Осипова Алена (CC BY-SA 4.0)
Mineral NameAmethyst
Chemical FormulaSiO2
Mohs Hardness7
Crystal Systemtrigonal
Lustervitreous
Streak ColorWhite
CleavageNone
FractureConchoidal
Specific Gravity2.65
Colorspurple, violet
TransparencyTransparent to translucent
Type LocalityBrazil, Uruguay, Zambia
Mineral GroupSilicates
Usesjewelry, collector, decorative, spiritual
Associated MineralsChalcedony, Calcite, Goethite, Hematite
Raritycommon
Description
A cluster of deep purple amethyst crystals, exhibiting well-formed terminations and a bright vitreous luster.
Geological Context
Amethyst typically forms in hydrothermal veins and geodes within volcanic rocks, where silica-rich fluids deposit quartz crystals at moderate temperatures. The purple color is due to irradiation and iron impurities.
