metamorphic

Serpentinite (likely antigorite-rich)

Serpentinite; chiefly serpentine-group minerals, approximately Mg₃Si₂O₅(OH)₄, with magnetite, carbonate, and possible chlorite/talc

AI-generated identification · may be incorrect

Dark green to black, mottled with tan and pale green patches; waxy to greasy luster and irregular fractured surfaces. Serpentine has Mohs hardness about 2.5–4, poor cleavage, generally massive texture, and specific gravity around 2.5–2.6; the image may also contain harder quartz or carbonate veins.

Identified September 5, 2026More metamorphic →

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At a glance

Common name: Serpentinite (likely antigorite-rich)
Scientific name: Serpentinite; chiefly serpentine-group minerals, approximately Mg₃Si₂O₅(OH)₄, with magnetite, carbonate, and possible chlorite/talc
Category: metamorphic
Identified: September 5, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a common hand specimen; $30–$150 for attractive polished or strongly patterned pieces.

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 ultramafic mantle rocks such as peridotite undergo hydration and metamorphism, commonly along oceanic crust, subduction zones, and major faults. Its exact age cannot be determined visually and may range from Paleozoic to modern tectonic settings.

Uses & applications

Used as decorative facing stone, carvings, countertops, and mineral specimens; historically used for ornamental objects. Avoid cutting or grinding unknown serpentinite because some varieties can contain fibrous asbestos minerals.

Geological facts

The distinctive green coloration comes from serpentine minerals, often accompanied by magnetite that can produce magnetic response. Some specimens are strongly veined and polished to resemble jade, but serpentinite is generally much softer.

Field identification & locations

Look for green-black mottling, waxy surfaces, low hardness, and possible magnetism; a steel nail may scratch it. Common in Alpine-type ultramafic belts, California, Italy, New Zealand, and many ophiolite complexes.