metamorphic
Polished green stone, likely serpentine or altered basalt
Serpentine-group minerals, chiefly Mg₃Si₂O₅(OH)₄; exact identification requires testing
AI-generated identification · may be incorrectPale green-gray, smooth polished surface, subdued waxy luster, and faint cream-colored veins. Serpentine hardness is about 2.5–4 Mohs with no obvious cleavage; the specimen appears rounded and tumbled.
Identified More metamorphic →
Explore Polished green stone, likely serpentine or altered basalt in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Pale green-gray, smooth polished surface, subdued waxy luster, and faint cream-colored veins. Serpentine hardness is about 2.5–4 Mohs with no obvious cleavage; the specimen appears rounded and tumbled.
Formation & geological history
Serpentine forms when ultramafic rocks hydrate during hydrothermal alteration, commonly in oceanic crust and subduction-zone mélanges. Formation ages vary widely, from Precambrian to recent tectonic settings.
Uses & applications
Used as an ornamental and carving stone, aggregate, and occasionally jewelry material. Polished pieces are mainly valued for appearance and collecting.
Geological facts
The photograph also shows several other polished geological specimens, including a porous pale rock and a black-and-white speckled igneous rock. The central stone cannot be identified with certainty from appearance alone.
Field identification & locations
Look for green color, waxy luster, low hardness, and pale veining; a steel nail may scratch it. Common sources include California, Italy, New Zealand, Canada, and southern Africa.
More like this
