metamorphic

Serpentine (likely antigorite-rich serpentinite)

Serpentine-group minerals, chiefly antigorite [(Mg,Fe)₃Si₂O₅(OH)₄]

AI-generated identification · may be incorrect

Dark olive-green to yellow-green, waxy to greasy luster, massive and finely fibrous with mottled veining; Mohs hardness about 2.5–4, poor cleavage, and specific gravity roughly 2.5–2.6. The smooth rounded surface appears polished or naturally water-worn.

Identified August 20, 2026More metamorphic →

Explore Serpentine (likely antigorite-rich serpentinite) 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: Serpentine (likely antigorite-rich serpentinite)
Scientific name: Serpentine-group minerals, chiefly antigorite [(Mg,Fe)₃Si₂O₅(OH)₄]
Category: metamorphic
Identified: August 20, 2026
Method: Standard

AI Estimated Value

About $5–$30 as a common hand specimen; $30–$150 if attractively polished, unusually patterned, or confirmed high-quality carving 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

Forms when ultramafic mantle rocks such as peridotite undergo hydration and low-temperature metamorphism, commonly in oceanic crust and tectonic belts. Individual serpentinite bodies may range from Precambrian to Cenozoic age; age cannot be determined visually.

Uses & applications

Used as ornamental stone, carvings, cabochons, countertops, and historically as a jade substitute; massive serpentinite also has limited aggregate and architectural use. Avoid cutting or inhaling dust because some serpentinite can contain asbestos-form serpentine minerals.

Geological facts

Its green color comes from iron-bearing serpentine and associated magnetite, chlorite, or talc. The specimen could also be nephrite-like material, but appearance alone cannot confirm jade.

Field identification & locations

Look for a low hardness, greasy/waxy surface, green-black mottling, and possible magnetism from magnetite; it commonly occurs in ophiolites and fault zones. Identification requires hardness, streak, density, and ideally thin-section or X-ray analysis.