gemstone

Tumbled purple gemstone, likely amethyst

Quartz (SiO₂), purple variety colored by trace iron and irradiation

AI-generated identification · may be incorrect

Hardness 7 Mohs; deep purple, vitreous luster, massive rather than visibly crystalline, with no cleavage and conchoidal fracture. The polished, rounded shape obscures diagnostic features, so identification from the photo is not certain.

Identified October 13, 2026More gemstone →

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Physical properties

Formation & geological history

Amethyst forms when silica-rich fluids deposit quartz in cavities and veins, commonly in volcanic rocks; deposits range from ancient to geologically recent.

Uses & applications

Used in jewelry, ornaments, and mineral collections; lower-grade pieces are also used for decorative objects.

Geological facts

Amethyst is quartz and is often sold tumbled; its color can fade with prolonged sunlight or heat.

Field identification & locations

The specimen appears to be a polished purple quartz pebble. Amethyst is common in Brazil, Uruguay, Zambia, and elsewhere; confirm with hardness or gemological testing because other purple minerals and dyed stones can look similar.