mineral

Tumbled amethyst

Quartz, SiO₂; purple coloration from iron-related defects and irradiation

AI-generated identification · may be incorrect

Mohs hardness 7; translucent lavender-purple color, vitreous luster, hexagonal crystal structure, and no cleavage with conchoidal fracture. The rounded, glossy shape indicates tumbling or polishing.

Identified August 26, 2026More mineral →

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Physical properties

Mohs hardness 7; translucent lavender-purple color, vitreous luster, hexagonal crystal structure, and no cleavage with conchoidal fracture. The rounded, glossy shape indicates tumbling or polishing.

Formation & geological history

Forms when silica-rich hydrothermal fluids fill cavities in volcanic rocks, especially basalt, where quartz crystals grow over geologic time, commonly from the Mesozoic to Cenozoic. The specimen has been human-processed.

Uses & applications

Used as an inexpensive gemstone, jewelry, ornament, meditation/collecting stone, and decorative aggregate. It has no established special healing properties beyond cultural belief.

Geological facts

Amethyst is the purple variety of quartz and is February’s birthstone. Heating can turn it yellow-orange, producing citrine or ametrine-like colors.

Field identification & locations

Identify by its purple quartz appearance, glassy luster, hardness, and lack of cleavage; common sources include Brazil, Uruguay, Zambia, and Bolivia. A scratch test should be avoided on finished pieces.