mineral

Tumbled green stone, possibly serpentine or aventurine

Serpentine-group minerals (mainly antigorite/lizardite) or quartz-rich green aventurine; image insufficient for certainty

AI-generated identification · may be incorrect

Small, rounded and polished, dark to medium green with a waxy-to-glassy luster. Serpentine is Mohs 2.5–4 and commonly massive with no visible cleavage; aventurine is quartz (Mohs 7) and may show mica sparkle. Specific gravity is roughly 2.5–2.7.

Identified September 14, 2026More mineral →

Explore Tumbled green stone, possibly serpentine or aventurine 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: Tumbled green stone, possibly serpentine or aventurine
Scientific name: Serpentine-group minerals (mainly antigorite/lizardite) or quartz-rich green aventurine; image insufficient for certainty
Category: mineral
Identified: September 14, 2026
Method: Standard

AI Estimated Value

$1–$10 as a common tumbled stone; attractive larger or unusual pieces may reach $15–$30.

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

Serpentine forms when ultramafic rocks hydrate during hydrothermal alteration; aventurine forms when quartz crystallizes with green mica or fuchsite. Both are geologically common, including in central Europe, but age cannot be determined from this photo.

Uses & applications

Used as tumbled stones, carvings, ornamental stone, and occasionally jewelry; serpentine is also used decoratively in slabs, while aventurine is popular for inexpensive cabochons.

Geological facts

The smooth shape indicates human tumbling or natural abrasion. A steel scratch test can help: serpentine scratches relatively easily, whereas quartz-rich aventurine does not.

Field identification & locations

The specimen is visually more consistent with polished serpentine than aventurine because it appears uniformly waxy and lacks obvious glitter. In the Thuringia area, serpentinized ultramafic rocks are a plausible regional source; confirm with hardness, streak, and a close examination for mica sparkle.