metamorphic
Greenstone / altered mafic rock
Likely chlorite–actinolite schist or metabasalt; exact identification requires testing
AI-generated identification · may be incorrectPale gray-green, fine- to medium-grained, dull to slightly silky luster, with weak foliation and granular texture. Estimated Mohs hardness 5–6; likely composed of chlorite, actinolite, epidote, albite, and minor quartz; cleavage is poor overall.
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Physical properties
Pale gray-green, fine- to medium-grained, dull to slightly silky luster, with weak foliation and granular texture. Estimated Mohs hardness 5–6; likely composed of chlorite, actinolite, epidote, albite, and minor quartz; cleavage is poor overall.
Formation & geological history
Probably metamorphosed basalt or other mafic volcanic rock during regional metamorphism, commonly in Precambrian to Paleozoic metamorphic belts. The tapered shape appears naturally weathered or possibly intentionally worked, but the image alone cannot establish age or artifact status.
Uses & applications
Used locally as durable building or paving stone and commonly collected as a field specimen; attractive green varieties may be polished for ornamental objects. It is generally low-value unless unusually vivid, well-foliated, or confirmed as a specific jade-like mineral.
Geological facts
“Greenstone” is a broad field term, not a single mineral or rock species, and can include altered basalt, schist, or amphibolite. It should not be called jade without hardness, density, and mineralogical testing.
Field identification & locations
Look for green color, fine grain, foliation, and a non-glassy surface; a steel nail or knife may scratch softer chlorite-rich material but not true jade. Common in metamorphic belts worldwide, including the Appalachians, Canadian Shield, New Zealand, and western North America.
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