mineral
Polished red jasper (likely brecciated or opaque chalcedony)
Jasper, microcrystalline quartz (SiO₂), commonly colored by iron oxides
AI-generated identification · may be incorrectHardness about 6.5–7 Mohs; opaque reddish-brown with darker internal patches, vitreous to waxy luster, and no visible cleavage. Its rounded, polished form obscures natural grain and fracture.
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Physical properties
Hardness about 6.5–7 Mohs; opaque reddish-brown with darker internal patches, vitreous to waxy luster, and no visible cleavage. Its rounded, polished form obscures natural grain and fracture.
Formation & geological history
Forms when silica-rich groundwater fills cavities or replaces volcanic and sedimentary material, with iron oxides producing the red color. Deposits commonly range from Precambrian to Cenozoic age.
Uses & applications
Used for cabochons, beads, carvings, tumbled stones, and ornamental objects; occasionally used as a decorative aggregate. This small polished piece is generally inexpensive.
Geological facts
Jasper is an opaque variety of chalcedony or microcrystalline quartz; color patterns are often diagnostic of a locality. The dark markings may indicate brecciation, manganese/iron staining, or another included mineral.
Field identification & locations
Common in volcanic terrains and silica-rich sedimentary formations worldwide, including India, Madagascar, Brazil, Australia, Mexico, and the western United States. Confirm with a hardness test against glass and inspection for a quartz-like, nonmetallic surface; the image alone cannot establish the exact variety.
