mineral

Amethyst

Quartz, violet variety — silicon dioxide (SiO₂) colored mainly by iron impurities and irradiation

AI-generated identification · may be incorrect

Typically Mohs hardness 7, vitreous luster, purple coloration, and conchoidal fracture with no cleavage; the specimen appears to be a rough, possibly partly polished fragment with visible quartz-like translucency.

Identified September 2, 2026More mineral →

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Physical properties

Formation & geological history

Forms in cavities of volcanic rocks, especially basaltic lava flows, when silica-rich hydrothermal fluids deposit quartz and amethyst crystals. Most specimens formed in Mesozoic to Cenozoic volcanic settings, though age varies by locality.

Uses & applications

Used as a gemstone, ornamental stone, carving material, and mineral specimen; common pieces have modest value, while intensely saturated, transparent crystals can be valuable.

Geological facts

Amethyst is the purple variety of quartz and is the birthstone for February. Its color can fade with prolonged heat or strong sunlight, and heating may produce yellow citrine.

Field identification & locations

Identify it by purple quartz, glassy luster, hardness sufficient to scratch ordinary glass, and absence of cleavage; common sources include Brazil, Uruguay, Zambia, and Bolivia. The image alone cannot confirm authenticity or locality.