metamorphic

Tumbled greenstone, likely serpentine or altered basalt

Serpentine-group minerals, chiefly Mg₃Si₂O₅(OH)₄; possibly chlorite/epidote-bearing mafic rock

AI-generated identification · may be incorrect

Olive-green to gray-green, fine-grained, matte to weakly waxy luster, rounded by tumbling; estimated Mohs hardness 3–6 depending on composition. No visible crystals or cleavage are apparent; specific gravity is roughly 2.6–3.2.

Identified September 10, 2026More metamorphic →

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At a glance

Common name: Tumbled greenstone, likely serpentine or altered basalt
Scientific name: Serpentine-group minerals, chiefly Mg₃Si₂O₅(OH)₄; possibly chlorite/epidote-bearing mafic rock
Category: metamorphic
Identified: September 10, 2026
Method: Standard

AI Estimated Value

About $1–$10 for a small common tumbled stone; potentially $10–$30 if identified as attractive high-quality jade-like material.

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

Most likely formed by hydrothermal metamorphism of ultramafic or mafic rock, with alteration of olivine and pyroxene; age cannot be determined from the photograph. It may also be a small altered basalt or greenstone pebble.

Uses & applications

Used as a decorative tumbled stone, carving material, lapidary cabochon, and occasionally ornamental building stone; typically not valuable as jewelry-grade material.

Geological facts

The term “greenstone” is descriptive rather than a single mineral name. Serpentine can resemble jade, but it is generally softer and less durable.

Field identification & locations

Look for olive coloration, mottled texture, waxy feel, and relatively low hardness; a steel knife may scratch serpentine but not jade. Common sources include serpentinite belts and metamorphic terrains worldwide.