mineral

Amethyst

SiO2 (Silicon Dioxide)

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Purple, violet, or lavender
Luster: Vitreous (glassy)

Identified June 29, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Purple, violet, or lavender; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in hydrothermal veins and basaltic geodes. Its purple color is the result of irradiation, iron impurities, and the presence of trace elements. Typically formed in the Cenozoic era for many common geodes.

Uses & applications

Primarily used in jewelry, as decorative collector specimens, and in alternative healing practices. Also used as a birthstone (February).

Geological facts

The color of amethyst is actually most stable in a specific temperature range; if heated to high temperatures (400-500 degrees Celsius), it can turn yellow or orange, becoming citrine.

Field identification & locations

Identify by its distinctive purple hue and hexagonal crystal prisms if uncut. Found globally with major deposits in Brazil and Uruguay. Look for crystals in volcanic rock cavities or stream beds near basaltic regions.