gemstone
Amethyst
Quartz (Silicon Dioxide, SiO2)
Hardness of 7 on the Mohs scale, purple to violet color, vitreous luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.
Identified More gemstone →
Explore Amethyst in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 7 on the Mohs scale, purple to violet color, vitreous luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.
Formation & geological history
Formed primarily within gas cavities (vesicles) in volcanic rocks (basalts) through the deposition of silica-rich solutions containing trace amounts of iron. Geological age varies greatly depending on the deposit, ranging from millions to over a billion years old.
Uses & applications
Widely used in jewelry, decorative items, lapidary art, and cherished by collectors for its striking purple coloration.
Geological facts
Amethyst was once considered one of the cardinal precious gemstones alongside diamond, ruby, sapphire, and emerald until large deposits were found in Brazil. Its purple color is caused by irradiation and trace iron impurities.
Field identification & locations
Easily identified by its distinct purple hue and quartz hardness (scratches glass). Found globally, with significant deposits in Brazil, Uruguay, Zambia, and the United States.
More like this
Other gemstone specimens
Diamond and Gold Jewelry
Carbon (Diamond) / Au (Gold)
gemstone
Ammolite
Ammolite (Biogenic Aragonite with trace elements; fossils of Placenticeras meeki and Placenticeras intercalare)
mineral
Cubic Zirconia (simulant) or Diamond
ZrO2 (Cubic Zirconia) or C (Diamond)
gemstone
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Black Opal Ring (Carved Opal)
Hydrated Silicon Dioxide (SiO2·nH2O)
gemstone
Cubic Zirconia (or possibly Diamond)
Zirconium dioxide (or Carbon)
gemstone