metamorphic
Tumbled greenstone (likely serpentine)
Serpentinite, composed chiefly of serpentine-group minerals (Mg₃Si₂O₅(OH)₄)
AI-generated identification · may be incorrectSmall, rounded, polished olive-green pebble with a waxy to slightly glossy luster and mottled color. Serpentine minerals are typically Mohs 2.5–5; individual grains and crystal structure cannot be confirmed from the photo.
Identified More metamorphic →
Explore Tumbled greenstone (likely serpentine) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Small, rounded, polished olive-green pebble with a waxy to slightly glossy luster and mottled color. Serpentine minerals are typically Mohs 2.5–5; individual grains and crystal structure cannot be confirmed from the photo.
Formation & geological history
Forms when water alters magnesium-rich ultramafic rocks, commonly along tectonic plate boundaries; the specimen’s age and exact source cannot be determined visually.
Uses & applications
Used as decorative stone, carvings, beads, and tumbled collectibles; some serpentinite is also used as building stone.
Geological facts
“Greenstone” is a broad trade term and can refer to several green rocks, so appearance alone cannot establish the precise mineral identity.
Field identification & locations
The smooth, rounded finish indicates tumbling or polishing. Serpentinite occurs worldwide in ancient and active mountain belts; hardness and mineral tests, or a locality label, would help distinguish it from jade or other green stones.
More like this
Other metamorphic specimens
Nephrite Jade
Nephrite
Mineral/Rock
Amphibolite
Amphibolite
metamorphic
Rhodonite
Manganese Silicate (Mn, Fe, Mg, Ca)SiO3
mineral
Rhodonite
(Mn,Fe,Mg,Ca)SiO3
mineral
Greenschist
Greenschist (containing Chlorite, Actinolite, and Epidote)
metamorphic
Garnet
Garnet group: X3Y2(SiO4)3 (commonly Almandine-Pyrope series)
mineral