mineral

Tumbled amethyst

Amethyst, purple quartz (SiO₂) colored primarily by iron impurities and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; purple to violet with vitreous luster, typically translucent, and no cleavage; trigonal crystal structure, though tumbling has rounded the original form. The visible reddish-brown areas may be iron staining or matrix inclusions.

Identified September 7, 2026More mineral →

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Physical properties

Formation & geological history

Forms mainly in cavities of volcanic rocks, where silica-rich groundwater deposits quartz over long periods; color develops from iron-related defects and natural radiation. Specimen age depends on its host deposit, commonly Paleozoic to Cenozoic.

Uses & applications

Used as a low-cost gemstone, ornamental stone, carvings, beads, and metaphysical specimens; polished pieces have modest decorative value.

Geological facts

Amethyst is the purple variety of quartz and is February’s birthstone. Prolonged heating or sunlight can fade its color or convert it toward yellow citrine tones.

Field identification & locations

Identify by its glassy purple color, hardness, and inability to scratch with a steel knife; quartz will scratch ordinary glass. Common sources include Brazil, Uruguay, Zambia, and Namibia; the image alone cannot confirm natural versus dyed material.