mineral

Tumbled green aventurine (probable)

Quartzite composed chiefly of microcrystalline quartz (SiO₂), with green mica or fuchsite inclusions

AI-generated identification · may be incorrect

Pale green-blue, rounded and polished, with a dull-to-vitreous luster and possible subtle aventurescence; quartz hardness is about 7 Mohs, with no obvious cleavage and typical specific gravity near 2.6. The image alone cannot confirm composition, and it could also be serpentine or another green stone.

Identified September 15, 2026More mineral →

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Physical properties

Formation & geological history

Aventurine forms when quartz-rich rock recrystallizes and incorporates reflective mica inclusions, commonly during metamorphism; individual specimens lack a precise age without provenance. Green quartzite deposits are widespread in Brazil, India, Russia, and Tanzania.

Uses & applications

Used for beads, carvings, cabochons, ornaments, and decorative stone; polished pieces are inexpensive collector or lapidary material.

Geological facts

The glittering effect called aventurescence comes from aligned mica or hematite platelets; this specimen appears relatively subdued, possibly because of its lighting or surface wear.

Field identification & locations

Check for quartz-like hardness by testing glass cautiously, inspect for mica sparkle, and compare streak and density; serpentine is softer (about 3–5 Mohs). Common tumbled pieces sell for about $2–$15; larger or strongly chatoyant specimens may reach $20–$50.