mineral

Tumbled purple quartz, possibly amethyst

Quartz (SiO₂), likely iron-colored amethyst or purple chalcedony

AI-generated identification · may be incorrect

Hardness 7; translucent purple-gray color with a dull to vitreous luster and no obvious cleavage. The rounded, abraded surface indicates natural or human tumbling; crystal structure is trigonal quartz, though individual crystals are not visible.

Identified August 16, 2026More mineral →

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Physical properties

Formation & geological history

Quartz formed from silica-rich hydrothermal fluids in cavities or veins, with trace iron producing purple coloration; the specimen was likely later weathered and tumbled. Exact geological age and locality cannot be determined from the image.

Uses & applications

Used as a lapidary and inexpensive jewelry/ornamental stone; quartz is also important in glass, electronics, and abrasives. This small specimen has modest collector value.

Geological facts

True amethyst usually shows clearer purple coloration and often visible crystal faces or zoning; opaque, mauve material may instead be purple chalcedony or dyed quartz.

Field identification & locations

Look for hardness sufficient to scratch glass, conchoidal fracture, and absence of strong cleavage; avoid destructive testing on valuable pieces. Common sources include Brazil, Uruguay, Zambia, and Madagascar.