mineral

Likely tumbled or polished dark purple mineral

Possibly amethyst (purple quartz, SiO₂), though the image is insufficient for confident identification

AI-generated identification · may be incorrect

Violet-gray, translucent to opaque, with a glassy luster and irregular fracture; quartz hardness is 7 Mohs, trigonal crystal structure, and no cleavage. The dark appearance may result from inclusions, coating, or low lighting.

Identified September 18, 2026More mineral →

Explore Likely tumbled or polished dark purple mineral in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

At a glance

Common name: Likely tumbled or polished dark purple mineral
Scientific name: Possibly amethyst (purple quartz, SiO₂), though the image is insufficient for confident identification
Category: mineral
Identified: September 18, 2026
Method: Standard

AI Estimated Value

Approximately $2–$20 if a small common polished amethyst; $20–$100+ if unusually vivid, transparent, and well-finished.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

If amethyst, it formed when iron-bearing quartz crystallized in gas cavities of volcanic rocks, commonly during the Mesozoic to Cenozoic. Geological age cannot be determined from the photograph.

Uses & applications

Amethyst is used for jewelry, ornaments, and mineral collecting; lower-grade material is sold as polished stones. Value depends strongly on color, transparency, and treatment.

Geological facts

The specimen could also be purple fluorite, glass, or another coated mineral; a clear view of crystal faces and tests are needed.

Field identification & locations

Check for consistent purple color, quartz-like glassy fracture, and hardness: it should scratch ordinary glass but not be scratched by steel. Common amethyst sources include Brazil, Uruguay, Zambia, and Mexico.