metamorphic

Greenstone (likely altered basalt or serpentinite)

Chlorite-rich metabasalt or serpentinite; exact identification requires testing

AI-generated identification · may be incorrect

Dark green, fine-grained, dull to slightly waxy luster, massive texture, and irregular fractures. Likely Mohs hardness 3–6 depending on composition; no visible cleavage or crystals.

Identified August 13, 2026More metamorphic →

Explore Greenstone (likely altered basalt or serpentinite) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Dark green, fine-grained, dull to slightly waxy luster, massive texture, and irregular fractures. Likely Mohs hardness 3–6 depending on composition; no visible cleavage or crystals.

Formation & geological history

Probably a weathered mafic volcanic rock altered by low-grade metamorphism or hydrothermal fluids; such rocks commonly formed in ancient oceanic crust, often Paleozoic or older.

Uses & applications

Used locally as crushed aggregate, landscaping stone, or carving material; attractive pieces may be collected, but this specimen has little commercial gemstone value.

Geological facts

“Greenstone” is a field term rather than one mineral species and may include chlorite schist, epidote-rich basalt, or serpentinite.

Field identification & locations

Green color and fine-grained massive texture support altered basalt or serpentinite. Check streak, hardness, density, magnetic response, and whether a fresh surface shows black pyroxene or fibrous/waxy serpentine; common in ophiolites and metamorphic belts.