metamorphic
Iron-rich jasper (likely brecciated jasper)
Microcrystalline quartz/chalcedony (SiO₂) colored by hematite/goethite; possibly iron formation
AI-generated identification · may be incorrectTypically hardness 6.5–7 Mohs, opaque, reddish-brown to maroon with gray-green patches, and dull to waxy or locally vitreous luster. It has no visible cleavage, conchoidal fracture, and specific gravity around 2.6–2.8.
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Physical properties
Typically hardness 6.5–7 Mohs, opaque, reddish-brown to maroon with gray-green patches, and dull to waxy or locally vitreous luster. It has no visible cleavage, conchoidal fracture, and specific gravity around 2.6–2.8.
Formation & geological history
Silica-rich fluids or sediments became cemented and locally altered, with iron oxides producing the red-brown color; some examples form in volcanic or banded-iron environments. Exact age cannot be determined from the photograph.
Uses & applications
Used as ornamental stone, cabochons, beads, carvings, and tumbled material; massive low-grade pieces have little industrial value.
Geological facts
The red coloration generally comes from finely disseminated hematite, while yellow-brown areas may contain goethite or limonite. Green patches could be chlorite, epidote, or altered host rock.
Field identification & locations
Identify by its dense, opaque character, red iron staining, and ability to scratch glass; a streak test may be reddish-brown. Common sources include India, Australia, Brazil, South Africa, and the western United States, but laboratory testing is needed for a precise identification.
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