metamorphic

Greenschist (likely chlorite schist)

Greenschist-facies metamorphic rock; commonly quartz + chlorite ± actinolite, epidote, albite, and mica

AI-generated identification · may be incorrect

Typically dark green-gray, fine- to medium-grained, with weak to strong schistosity and a dull to subtly sparkly luster. Hardness is roughly 5–6 overall; individual quartz grains are Mohs 7, and cleavage follows aligned mica/chlorite.

Identified September 17, 2026More metamorphic →

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At a glance

Common name: Greenschist (likely chlorite schist)
Scientific name: Greenschist-facies metamorphic rock; commonly quartz + chlorite ± actinolite, epidote, albite, and mica
Category: metamorphic
Identified: September 17, 2026
Method: Standard

AI Estimated Value

Approximately $5–$30 for a common hand specimen; $30–$100 for unusually attractive, large, or well-labeled examples.

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

Formed when basaltic or other mafic volcanic rock undergoes low- to medium-grade regional metamorphism, commonly during mountain building. It may range from Precambrian to recent geological settings, depending on the terrain.

Uses & applications

Used locally as crushed stone, aggregate, landscaping rock, and occasionally dimension stone; attractive foliated pieces are collected but are rarely high-value jewelry material.

Geological facts

Its green color mainly reflects chlorite, actinolite, and epidote. The specimen’s fine foliation and granular texture are consistent with greenschist, though a photograph cannot exclude fine-grained amphibolite or altered basalt.

Field identification & locations

Common in metamorphic belts worldwide, including the Alps, Appalachians, New England, British Isles, and Pacific Northwest. Look for planar splitting, green minerals, weak sparkle, and a non-vesicular texture; acid reaction should be absent.