mineral

Amethyst-bearing quartz

Quartz, SiO₂; purple variety colored mainly by iron-related defects

AI-generated identification · may be incorrect

Hardness 7 Mohs, vitreous luster, conchoidal fracture, and trigonal crystal structure; typically transparent to translucent with purple, gray, and milky zones. The photographed pieces appear rough and partly weathered, possibly amethyst quartz or quartz-rich rock.

Identified August 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids fill cavities in volcanic rocks, commonly alongside iron minerals; many specimens formed in Mesozoic to Cenozoic volcanic environments. Exact identification and age require locality or testing.

Uses & applications

Used as a gemstone, ornamental stone, crystal specimen, and source material for carvings; quartz also has major industrial uses in glass, ceramics, abrasives, and electronics.

Geological facts

Purple color intensity depends on iron impurities and irradiation, and can fade with prolonged heat or strong sunlight. Amethyst commonly occurs as crystal-lined geodes.

Field identification & locations

Look for purple zoning, glassy luster, hardness sufficient to scratch ordinary glass, and lack of cleavage; confirm with streak, specific gravity (~2.65), or microscopy. Common sources include Brazil, Uruguay, Zambia, and Arizona.