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, pale lilac
Transparencytransparent
Type LocalitySahatany Pegmatite Field (Mt Bity (Ibity) area), Vakinankaratra Region, Madagascar
Mineral GroupSilicates
Usesjewelry, collector, ornamental
Associated Mineralsquartz, feldspar, mica
Rarityuncommon
Description
This specimen features multiple clusters of pale to medium purple amethyst crystals, exhibiting well-formed crystal habits, growing on a lighter-colored, possibly quartz or feldspar matrix.
Geological Context
Amethyst, a variety of quartz, typically forms in hydrothermal solutions filling cavities (geodes, vugs) or veins within igneous rocks, particularly volcanic basalts, or in pegmatites. Its characteristic purple color is attributed to irradiation of iron impurities within the crystal lattice.
