igneous
Tumbled orbicular stone, possibly kambaba jasper
Likely orbicular rhyolite or related silica-rich rock; exact identification is uncertain from the image
AI-generated identification · may be incorrectRounded, polished pebble with dark green-black circular spots in a pale green matrix. If rhyolitic, hardness is about 6–7 Mohs; the visible pattern is mineral texture, not crystal cleavage, and the surface has a polished, low-gloss luster.
Identified More igneous →
Explore Tumbled orbicular stone, possibly kambaba jasper in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Rounded, polished pebble with dark green-black circular spots in a pale green matrix. If rhyolitic, hardness is about 6–7 Mohs; the visible pattern is mineral texture, not crystal cleavage, and the surface has a polished, low-gloss luster.
Formation & geological history
Orbicular textures form as minerals crystallize in concentric or clustered patterns within cooling magma. The specific source and geological age cannot be determined from the photograph.
Uses & applications
Primarily a decorative or lapidary stone, used for tumbling, small carvings, and collecting; not commonly used as a building stone.
Geological facts
The pattern resembles stones sold as kambaba jasper, though that trade name is often applied to orbicular rocks and does not establish a precise geological identity.
Field identification & locations
Look for rounded dark spots embedded throughout a green matrix and a naturally hard, polishable surface. Similar patterned material is sold from several localities, so provenance or testing is needed for confident identification.
