mineral

Tumbled purple quartz, possibly amethyst

Quartz (SiO₂), likely purple amethyst colored by trace iron

AI-generated identification · may be incorrect

Hardness 7 Mohs; translucent purple body with a vitreous luster and conchoidal fracture. Quartz is trigonal and lacks cleavage; the rounded surface indicates tumbling or polishing.

Identified September 7, 2026More mineral →

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Physical properties

Hardness 7 Mohs; translucent purple body with a vitreous luster and conchoidal fracture. Quartz is trigonal and lacks cleavage; the rounded surface indicates tumbling or polishing.

Formation & geological history

Amethyst forms when iron-bearing silica-rich fluids fill cavities in volcanic rocks, commonly basalt, and crystallize over long periods. The specimen’s exact age and locality cannot be determined from the image.

Uses & applications

Used as an inexpensive gemstone, ornament, metaphysical collectible, and decorative tumbled stone; quartz is also important industrially in glass, electronics, and abrasives.

Geological facts

Amethyst is the purple variety of quartz, with color ranging from pale lilac to deep violet. Heating can alter its color and produce yellow citrine-like material.

Field identification & locations

Look for purple coloration, glassy luster, translucent edges, and hardness sufficient to scratch ordinary glass; a scratch test should be avoided on polished pieces. Common sources include Brazil, Uruguay, Zambia, and Mexico.