mineral
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Hardness: 7 (Mohs), Color: Purple to violet, Luster: Vitreous/glassy, Crystal system: Trigonal/Hexagonal, 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 (Mohs), Color: Purple to violet, Luster: Vitreous/glassy, Crystal system: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65
Formation & geological history
Formed in hydrothermal veins or as linings in geodes within igneous rocks. The purple color is caused by natural irradiation of trace trivalent iron impurities and structural defects in the quartz lattice.
Uses & applications
Primarily used in jewelry, as decorative display specimens, and in metaphysical practices. It is the birthstone for February.
Geological facts
Until the discovery of large deposits in Brazil in the 19th century, amethyst was considered one of the five cardinal gemstones alongside diamonds, rubies, sapphires, and emeralds.
Field identification & locations
Identify by its characteristic purple color and hexagonal crystal habit when raw; in the field, it is often found inside volcanic geodes. Look for clarity and intensity of color. Commonly found in Brazil, Uruguay, and Zambia.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Sandstone with Mineral Veining or Crust
Sedimentary Sandstone (mostly SiO2 with Fe2O3 tinting)
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock