metamorphic

Greenstone / serpentinized rock

Serpentinite, commonly dominated by serpentine-group minerals (antigorite, lizardite, or chrysotile)

AI-generated identification · may be incorrect

Typically olive to yellow-green, mottled, waxy to dull luster, and massive with no obvious crystals; Mohs hardness about 2.5–4, with variable specific gravity around 2.5–2.7. The wet, polished-looking surface and dark veining fit a serpentinized ultramafic rock, though the photograph cannot exclude greenstone or nephri…

Identified September 11, 2026More metamorphic →

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At a glance

Common name: Greenstone / serpentinized rock
Scientific name: Serpentinite, commonly dominated by serpentine-group minerals (antigorite, lizardite, or chrysotile)
Category: metamorphic
Identified: September 11, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a common hand specimen; $30–$150 if unusually attractive, polished, or confirmed as high-quality ornamental serpentine.

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

Forms when mantle-derived peridotite is hydrated and metamorphosed, commonly along tectonic plate boundaries and ophiolite belts. Serpentinization is mainly Mesozoic to younger in many exposed belts, but the age depends on locality.

Uses & applications

Used as ornamental stone, carvings, countertops, and aggregate; attractive material may be sold as “new jade” or serpentine, though it is not true jade.

Geological facts

Field tests include a waxy feel, low hardness, pale green streak, and possible magnetism from associated magnetite. True nephrite is tougher and harder (about 6–6.5) and generally has a fibrous texture.

Field identification & locations

Common in California, Vermont, Italy, New Zealand, and many ophiolite complexes. Avoid cutting or sanding unknown serpentinite because some varieties may contain chrysotile asbestos.