mineral
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Hardness: 7 (Mohs), Color: Purple to violet with white/clear quartz banding, Luster: Vitreous (glassy) when polished, Crystal structure: Trigonal/Hexagonal, Specific Gravity: 2.65
Identified More mineral →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs), Color: Purple to violet with white/clear quartz banding, Luster: Vitreous (glassy) when polished, Crystal structure: Trigonal/Hexagonal, Specific Gravity: 2.65
Formation & geological history
Formed in hydrothermal veins or volcanic geodes where silica-rich fluids permeate cavities. The purple color is caused by irradiation of trivalent iron (Fe3+) in the quartz structure.
Uses & applications
Extensively used in jewelry, lapidary arts (carvings and polished shapes), and as a popular collector's mineral.
Geological facts
Amethyst was once considered one of the 'Cardinal Gems' along with diamond and ruby. The name comes from the Greek 'amethystos', meaning 'not intoxicated', as it was believed to prevent drunkenness.
Field identification & locations
Commonly found in Brazil, Uruguay, and Zambia. Identify by its purple color, hardness (it can scratch glass), and lack of cleavage. Often shows 'color zoning' or translucent banding.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Nephrite Jade
Nephrite
Mineral/Rock
Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety often found as a river rock)
Metamorphic Rock
![Biotite Schist (Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]) — metamorphic](https://media.rock.id/9ca564b5-bc87-402b-965a-69b21f9aa6bf-thumbnail.jpg)
Biotite Schist
Biotite-rich Schist [K(Mg,Fe)3AlSi3O10(F,OH)2]
metamorphic