gemstone

Tumbled amethyst

Quartz, purple variety — SiO₂, colored mainly by iron impurities and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; purple to violet, translucent, and vitreous with conchoidal fracture; trigonal crystal structure, no cleavage, specific gravity about 2.65. The rounded shape indicates tumbling or polishing.

Identified August 9, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids fill cavities in volcanic rocks, especially basaltic lava flows; purple quartz commonly develops during later oxidation and irradiation. Major deposits are geologically young to Phanerozoic, notably in Brazil, Uruguay, Zambia, and Bolivia.

Uses & applications

Used for cabochons, beads, carvings, decorative objects, and inexpensive jewelry; large crystal geodes are popular display specimens.

Geological facts

Amethyst is the February birthstone and the most valued quartz variety. Prolonged sunlight or heat can fade its purple color or convert it toward yellow-orange citrine.

Field identification & locations

Identify it by its purple color, glassy luster, hardness, and lack of cleavage; quartz will scratch glass but not usually be scratched by a steel knife. This image appears to show a small polished/tumbled piece, though lighting and surface treatment limit certainty.