mineral

Tumbled amethyst

Quartz, purple variety; silicon dioxide (SiO₂), colored mainly by iron impurities and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; translucent to opaque purple-brown body, vitreous luster, and conchoidal fracture. The rounded shape indicates mechanical tumbling; crystal faces and cleavage are absent or obscured.

Identified September 4, 2026More mineral →

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Physical properties

Mohs hardness 7; translucent to opaque purple-brown body, vitreous luster, and conchoidal fracture. The rounded shape indicates mechanical tumbling; crystal faces and cleavage are absent or obscured.

Formation & geological history

Amethyst forms when iron-bearing quartz crystallizes in cavities of volcanic rocks, especially basalt and rhyolite, and later develops purple color through natural irradiation. Most deposits are Cenozoic to older, depending on locality.

Uses & applications

Commonly sold as a lapidary stone, cabochon, jewelry component, ornament, or inexpensive metaphysical specimen; it has no major construction use.

Geological facts

Color can fade with prolonged heat or strong sunlight. Natural amethyst typically shows internal zoning, veils, or tiny inclusions, while uniformly dark material may be dyed or heat-treated.

Field identification & locations

Identify it by purple coloration, glassy luster, hardness sufficient to scratch ordinary glass, and quartz-like conchoidal fracture; common sources include Brazil, Uruguay, Zambia, and Morocco.