metamorphic

Waterworn greenstone pebble

Likely serpentinite or chlorite-rich metamorphic rock; exact identification requires testing

AI-generated identification · may be incorrect

Hardness typically 3–6 Mohs; olive-green, brown, and reddish mottling; wet vitreous-to-waxy luster; massive, fine-grained texture with no visible cleavage. Rounded shape and glossy surface result from stream abrasion.

Identified August 10, 2026More metamorphic →

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At a glance

Common name: Waterworn greenstone pebble
Scientific name: Likely serpentinite or chlorite-rich metamorphic rock; exact identification requires testing
Category: metamorphic
Identified: August 10, 2026
Method: Standard

AI Estimated Value

About $2–$15 as a common waterworn pebble; $20–$100 if confirmed as attractive serpentinite, jade-like material, or a high-quality lapidary specimen.

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

Probably formed by low- to moderate-grade metamorphism or hydrothermal alteration of ultramafic rock, potentially millions to billions of years ago, then transported and polished in a stream. The image alone cannot establish its geological age or exact composition.

Uses & applications

Suitable mainly as a decorative pebble, lapidary/tumbled stone, or collector specimen; serpentinite may be carved, while harder greenstones can be used for ornaments and minor construction aggregate.

Geological facts

Green coloration commonly comes from serpentine, chlorite, or epidote minerals; reddish-brown areas may reflect iron oxides. A streak, hardness, specific-gravity, and acid test would distinguish serpentinite from jasper, basalt, or altered schist.

Field identification & locations

Look for a smooth stream-worn form, mottled green color, waxy sheen, and low-to-moderate density; common in rivers draining ultramafic or metamorphic terrains. Avoid assuming jade from color alone—jade is notably tougher and typically harder.