metamorphic

Tumbled greenstone (likely serpentine or chlorite-rich basalt)

Serpentinite, principally serpentine-group minerals: Mg₃Si₂O₅(OH)₄; exact identification requires testing

AI-generated identification · may be incorrect

Dark olive-green, fine-grained, smoothly tumbled, with waxy to subvitreous luster and white vein-like inclusions. Typical hardness is Mohs 2.5–4; cleavage is poor or absent, and specific gravity is about 2.5–2.7.

Identified September 21, 2026More metamorphic →

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At a glance

Common name: Tumbled greenstone (likely serpentine or chlorite-rich basalt)
Scientific name: Serpentinite, principally serpentine-group minerals: Mg₃Si₂O₅(OH)₄; exact identification requires testing
Category: metamorphic
Identified: September 21, 2026
Method: Standard

AI Estimated Value

About $2–$15 for a small tumbled stone; $20–$100+ for unusually patterned polished specimens.

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

Serpentinite forms when magnesium-rich ultramafic rocks chemically react with water, commonly in oceanic crust and tectonic suture zones; ages range from Precambrian to present. The white markings may be quartz, carbonate, or talc veins.

Uses & applications

Used as ornamental stone, carvings, beads, countertops, and lapidary material; attractive pieces have modest jewelry and collecting value.

Geological facts

Serpentine commonly resembles jade but is generally softer and less dense. Some serpentinite contains chrysotile asbestos, so avoid cutting or grinding unknown material and do not inhale dust.

Field identification & locations

Field clues include green color, waxy surface, low hardness, and dark veining; it may be scratched by a steel knife. Common sources include California, Vermont, Italy, New Zealand, and Japan.