mineral

Tumbled green aventurine (probable)

Quartz, SiO₂, with green mica/fuchsite inclusions

AI-generated identification · may be incorrect

Polished, translucent-to-opaque dark green stone with a glassy luster and internal planar fractures/inclusions. Quartz hardness is about 7 Mohs; specific gravity about 2.65; no obvious cleavage. The apparent flash may come from mica or a polished fracture.

Identified September 15, 2026More mineral →

Explore Tumbled green aventurine (probable) in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Usually formed in quartz-rich metamorphic or hydrothermal rocks, where fuchsite or other minerals color the quartz green; the natural material is commonly Precambrian to Paleozoic in age, depending on source.

Uses & applications

Commonly sold as inexpensive tumbled material, cabochons, carvings, beads, and decorative stone; not generally used as a structural stone in this form.

Geological facts

The specimen is strongly consistent with aventurine quartz, though serpentine or dyed green quartzite are alternatives without a hardness, streak, or magnification test.

Field identification & locations

Test a hidden spot: quartz should resist scratching with a steel knife, while true green aventurine often shows tiny glittering mica flakes. Aventurine is widely marketed from India, Brazil, Russia, and China; the Guerrero-area location is compatible with varied volcanic and metamorphic material but does not uniquely identify its source.