sedimentary

Jasper (likely brecciated red jasper)

Microcrystalline quartz/chalcedony (SiO₂), commonly iron-oxide stained

AI-generated identification · may be incorrect

Typically opaque red-brown with gray or tan fragments, earthy to dull/waxy luster, and irregular fractures; hardness about 6.5–7 Mohs, no cleavage, cryptocrystalline structure, and specific gravity near 2.6.

Identified August 19, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater cements fine sediment or breccia, with iron oxides producing the red coloration. Jasper deposits occur in many ages, commonly in volcanic or hydrothermal environments.

Uses & applications

Used for cabochons, beads, carvings, lapidary pieces, and ornamental stone; rarely used as aggregate or decorative building material.

Geological facts

Brecciated jasper contains angular fragments cemented by later silica and may show striking red, brown, gray, or black patterns. Its color is mainly caused by hematite or other iron oxides.

Field identification & locations

Identify it by its opaque coloration, very fine texture, lack of visible grains or cleavage, and inability to scratch it with a steel knife; quartz or glass should scratch it. Common sources include Arizona, California, Oregon, India, Madagascar, and Australia.