mineral
Amethyst
Quartz (SiO2)
AI-generated identification · may be incorrectHardness: 7 on the Mohs scale, Color: Purple to violet, Luster: Vitreous (glassy), Crystal Structure: Trigonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65
Identified More mineral →
Explore Amethyst in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on the Mohs scale, Color: Purple to violet, Luster: Vitreous (glassy), Crystal Structure: Trigonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65
Formation & geological history
Formed in gas cavities (vesicles) in basaltic volcanic rocks, or in hydrothermal veins, where silica-rich solutions deposit quartz crystals at low to moderate temperatures.
Uses & applications
Widely used as a gemstone in jewelry, decorative items, and by collectors. Also historically valued as an amulet.
Geological facts
The purple color is caused by irradiation, iron impurities, and the presence of trace elements. Amethyst was once considered one of the cardinal precious gemstones.
Field identification & locations
Easily identified by its distinct purple color and vitreous luster. Found worldwide, with notable deposits in Brazil, Uruguay, and parts of the USA (such as North Carolina).
More like this
Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Septarian Pebble
Septarian nodule / Concretion
sedimentary