mineral

Amethyst

Amethyst (SiO2 - Silicon Dioxide with iron impurities)

Hardness: 7 on Mohs scale; Color: Purple to violet; Luster: Vitreous (glass-like); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Purple to violet
Luster: Vitreous (glass-like)

Identified February 5, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Purple to violet; Luster: Vitreous (glass-like); Crystal structure: Hexagonal/Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in igneous or sedimentary cavities (vugs) when silica-rich hydrothermal fluids crystallize into quartz. The purple color is caused by trace amounts of iron and natural irradiation within the earth. Major deposits range from several million to hundreds of millions of years old.

Uses & applications

Predominantly used as a gemstone in jewelry (rings, necklaces, earrings) and as decorative specimens or metaphysical clusters for collectors.

Geological facts

Until the 18th century, amethyst was considered one of the 'Cardinal Gems' along with diamond, ruby, emerald, and sapphire, before large deposits were found in Brazil; it is the birthstone for February.

Field identification & locations

Identify by its characteristic purple color and six-sided prismatic crystals. It is commonly found in Brazil (Parana Basin), Uruguay, Zambia, and South Korea. For identification, look for the 'vug' or geode casing on the back of the crystals.

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