mineral

Polished blue-purple quartz pebble, possibly amethyst

Quartz (SiO₂), likely iron-colored amethyst or fluorite-like material

AI-generated identification · may be incorrect

Hardness about 7 if quartz; translucent blue-violet and brown zoning, vitreous luster, no visible cleavage, and a granular/crystalline interior beneath polish. The image alone cannot confirm mineral identity; fluorite would be softer (Mohs 4) and have cubic cleavage.

Identified August 26, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed in hydrothermal veins or cavities and later tumbled/polished; quartz varieties commonly formed from silica-rich fluids over broad geological timescales, from Precambrian to recent deposits.

Uses & applications

Used as a decorative or collectible pebble; amethyst is also used in jewelry, carvings, and specimens. Small polished pieces have modest commercial value.

Geological facts

Purple coloration in amethyst is mainly associated with iron impurities and irradiation; the blue-violet/brown appearance may also indicate dyed or coated quartz.

Field identification & locations

Check hardness with an inconspicuous area, streak, transparency, and cleavage; quartz should scratch glass and leave a white streak, while fluorite will not. Common sources include Brazil, Uruguay, Mexico, and Madagascar.