mineral

Amethyst

Silicon Dioxide with iron impurities (SiO2)

Hardness: 7 on Mohs scale; Color: transparent purple to violet; Luster: vitreous (glassy); Crystal Structure: hexagonal (trigonal); Cleavage: none (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: transparent purple to violet
Luster: vitreous (glassy)

Identified February 22, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: transparent purple to violet; Luster: vitreous (glassy); Crystal Structure: hexagonal (trigonal); Cleavage: none (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in geothermal environments, often in volcanic rock cavities (geodes) or hydrothermal veins when silica-rich water cools and crystallizes at temperatures between 50°C and 250°C

Uses & applications

Primarily used in jewelry making (faceted or cabochon), decorative carvings, and as a popular specimen for mineral collectors

Geological facts

The purple color is caused by trace amounts of iron and natural irradiation within the earth. It was once considered as valuable as diamonds until large deposits were discovered in Brazil in the 19th century.

Field identification & locations

Identify by its characteristic purple color and hexagonal prism shape. Commonly found in Brazil, Uruguay, Zambia, and South Korea. Collectors should look for deep, uniform color and high clarity.

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