mineral
Polished brecciated jasper
Jasper, microcrystalline quartz (SiO₂), with iron-oxide inclusions
AI-generated identification · may be incorrectTypically opaque, multicolored red, yellow, brown, and cream with a glassy-to-waxy polish; hardness about 6.5–7 Mohs, cryptocrystalline structure, no visible cleavage, and specific gravity near 2.6. The pictured piece appears tumbled or polished.
Identified More mineral →
Explore Polished brecciated jasper in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Typically opaque, multicolored red, yellow, brown, and cream with a glassy-to-waxy polish; hardness about 6.5–7 Mohs, cryptocrystalline structure, no visible cleavage, and specific gravity near 2.6. The pictured piece appears tumbled or polished.
Formation & geological history
Forms when silica-rich fluids cement and replace fine sediments or volcanic material, with iron oxides producing the red and yellow colors; ages vary widely, commonly Paleozoic to Cenozoic. Common in volcanic and sedimentary terrains.
Uses & applications
Used for cabochons, beads, carvings, ornamental objects, and inexpensive collector specimens; occasionally used as decorative stone.
Geological facts
Jasper is an opaque variety of chalcedony and quartz, unlike transparent gemstone-quality quartz. Brecciation creates angular color patches later cemented by silica.
Field identification & locations
Identify by its opaque patterned appearance, very fine texture, waxy luster, and inability to scratch with a steel knife; quartz or glass can scratch it. Common sources include India, Madagascar, Brazil, Australia, and the western United States.
