metamorphic

Weathered greenstone (probable)

Chlorite–actinolite–epidote-rich metamorphosed mafic rock; exact identification requires testing

AI-generated identification · may be incorrect

Pale green-gray, fine-grained and dull to weakly silky, with rusty-brown weathering on edges. Likely Mohs hardness about 5–6; minerals are too fine-grained to identify crystal structure or cleavage from the image.

Identified October 14, 2026More metamorphic →

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At a glance

Common name: Weathered greenstone (probable)
Scientific name: Chlorite–actinolite–epidote-rich metamorphosed mafic rock; exact identification requires testing
Category: metamorphic
Identified: October 14, 2026
Method: Standard

AI Estimated Value

Typically $1–$20 for a small, ordinary hand specimen; higher value would require unusual texture, provenance, or confirmed mineral content.

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

Likely formed when basalt or another mafic volcanic rock was altered by low-grade metamorphism and hydrothermal fluids. Its age cannot be determined from the photograph; greenstones occur in rocks of many ages.

Uses & applications

Commonly used as crushed aggregate, dimension stone, and occasionally for carving or decorative pieces; this specimen appears to have little gem value.

Geological facts

“Greenstone” describes a green-colored metamorphosed rock, not a single mineral or precise composition.

Field identification & locations

The green color and massive, fine-grained texture suggest greenstone, but the image alone cannot rule out other altered rocks. Check a fresh surface, hardness, and mineral grains; common settings include ancient volcanic belts and metamorphic terrains.