metamorphic
Red jasper pebble
Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides
AI-generated identification · may be incorrectTypically reddish-brown, opaque, fine-grained, and waxy to dull; Mohs hardness 6.5–7, no cleavage, conchoidal fracture, and specific gravity about 2.6. The smoothly rounded shape indicates natural water-worn or tumbled polishing.
Identified More metamorphic →
Explore Red jasper pebble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Typically reddish-brown, opaque, fine-grained, and waxy to dull; Mohs hardness 6.5–7, no cleavage, conchoidal fracture, and specific gravity about 2.6. The smoothly rounded shape indicates natural water-worn or tumbled polishing.
Formation & geological history
Forms when silica-rich fluids cement or replace sediment, concentrating hematite or other iron oxides; many examples are Precambrian to younger, depending on locality. Commonly occurs in volcanic-associated silica deposits, chert beds, and alluvial gravels.
Uses & applications
Used for cabochons, beads, carvings, ornaments, and lapidary specimens; crushed jasper can serve as decorative aggregate. It has little industrial value compared with ordinary quartz.
Geological facts
Jasper is technically a rock rather than a single mineral, usually containing microcrystalline quartz plus iron oxides and minor clays. Red color is a useful clue, but similar pebbles may be iron-stained chert or fine-grained volcanic rock.
Field identification & locations
Look for uniform opacity, red-brown iron staining, very fine texture, and glassy/conchoidal fracture; it should scratch glass but not be scratched by a steel knife. Common in India, Madagascar, Brazil, the United States, Australia, and many gravel deposits.
More like this
