Amethyst
Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/14730981@N08">James Petts</a> from London, England (CC BY-SA 2.0)
Mineral NameAmethyst
Chemical FormulaSiO2
Mohs Hardness7
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.65
Colorspurple, violet, white
Transparencytransparent
Type LocalityBrazil
Mineral Groupsilicates
Usesjewelry, collector, decorative
Associated Mineralsquartz, calcite, agate, zeolites
Raritycommon
Description
A cluster of vibrant purple, well-formed hexagonal amethyst crystals growing on a light-colored rock matrix, exhibiting a glassy luster.
Geological Context
Amethyst forms in hydrothermal veins and cavities within igneous rocks, particularly basaltic lavas, where silica-rich fluids deposit quartz crystals colored by iron impurities and natural irradiation.
