mineral
Tumbled jasper or iron-rich chert
Microcrystalline quartz (SiO₂), likely colored by iron oxides
AI-generated identification · may be incorrectOrange-brown, opaque, earthy to waxy luster with a rounded tumbled surface and possible lighter quartz or chalcedony patches; Mohs hardness about 6.5–7, no obvious cleavage, cryptocrystalline structure, and specific gravity near 2.6.
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Physical properties
Orange-brown, opaque, earthy to waxy luster with a rounded tumbled surface and possible lighter quartz or chalcedony patches; Mohs hardness about 6.5–7, no obvious cleavage, cryptocrystalline structure, and specific gravity near 2.6.
Formation & geological history
Forms when silica-rich fluids replace or cement sediment, with iron oxides producing the orange coloration; typically Paleozoic to younger, though the specimen’s age cannot be determined visually.
Uses & applications
Used for cabochons, beads, carvings, polished stones, and inexpensive collector specimens; generally not used as a major construction stone.
Geological facts
Jasper is an opaque variety of chalcedony or microcrystalline quartz, and its patterns commonly reflect mineral replacement, brecciation, or iron-rich fluids.
Field identification & locations
Commonly found in volcanic and sedimentary environments worldwide, including India, Madagascar, Brazil, Australia, and the western United States; hardness and inability to scratch it with a steel knife help distinguish it from softer orange rocks.
