Amethyst (Spirit Quartz variety)
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 (Spirit Quartz variety)
Chemical FormulaSiO2
Mohs Hardness7
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.65
Colorspurple, lavender, white, tan
Transparencytranslucent
Type LocalityBoekenhoutshoek area, Mkobola district, Mpumalanga Province, South Africa
Mineral GroupSilicates
Usesjewelry, collector, metaphysical
Associated Mineralsquartz
Rarityuncommon
Description
This specimen features a cluster of pale lavender to purple amethyst crystals, characterized by smaller secondary quartz crystals coating the faces of larger, underlying amethyst points, giving it a 'cactus' or 'spirit' appearance, all growing on a lighter quartz matrix.
Geological Context
Amethyst, a variety of quartz, typically forms in hydrothermal veins and geodes within volcanic rocks, where iron impurities and natural irradiation cause its distinctive purple color. This specific 'Spirit Quartz' formation is known from South Africa.
