mineral
Polished brown jasper or brecciated jasper
Microcrystalline quartz (SiO₂), commonly mixed with iron oxides and other silicates
AI-generated identification · may be incorrectOpaque brown, tan, and black mottling with a dull to waxy luster; quartz hardness is about 6.5–7 Mohs, with no obvious cleavage and a fine-grained cryptocrystalline structure. The surface appears cut or polished.
Identified More mineral →
Explore Polished brown jasper or brecciated jasper in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Opaque brown, tan, and black mottling with a dull to waxy luster; quartz hardness is about 6.5–7 Mohs, with no obvious cleavage and a fine-grained cryptocrystalline structure. The surface appears cut or polished.
Formation & geological history
Jasper forms when silica-rich fluids replace or cement sedimentary and volcanic material, while brecciated varieties preserve angular fragments and iron staining. Formation ages vary widely, commonly from Precambrian to younger volcanic settings.
Uses & applications
Used for cabochons, beads, carvings, ornaments, and lapidary specimens; occasionally used as decorative stone. It has little industrial value compared with ordinary quartz.
Geological facts
Jasper’s distinctive colors commonly come from hematite, goethite, or other iron oxides. The pictured angular pattern may indicate brecciation, but exact variety cannot be confirmed from the image alone.
Field identification & locations
Identify it by its opacity, fine texture, hardness, lack of cleavage, and red-brown iron-rich patterns; common sources include India, Madagascar, Brazil, Australia, and the western United States.
