mineral

Tumbled brecciated jasper

Silica-rich microcrystalline quartz/chalcedony (SiO₂), with iron-oxide and other mineral inclusions

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; mottled brown, gray, cream, and reddish colors; opaque, waxy to dull luster; microcrystalline quartz with no visible cleavage and conchoidal fracture. The rounded surface indicates tumbling or natural water wear.

Identified August 8, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids cement and replace fragmented volcanic or sedimentary material, with iron oxides producing red-brown coloration. Jasper deposits range from Precambrian to younger volcanic and sedimentary settings.

Uses & applications

Commonly used for cabochons, beads, carvings, polished stones, and decorative objects; low-grade material is used as aggregate or ornamental stone.

Geological facts

Brecciation—the angular contrasting fragments—is a key feature, though the specimen may also contain chalcedony, hematite, or volcanic rock fragments.

Field identification & locations

Identify it by its opacity, quartz-like hardness, irregular multicolor patches, and inability to scratch with a steel knife; it should scratch glass but not be scratched by it. Common sources include the western United States, Australia, Brazil, India, and Madagascar.