mineral

Tumbled jasper

Microcrystalline quartz (SiO₂), commonly iron-rich jasper

AI-generated identification · may be incorrect

Opaque mustard-brown, smoothly polished, with dull-to-waxy luster; quartz hardness is about 6.5–7 Mohs, no cleavage, and specific gravity near 2.6. The rounded shape indicates mechanical tumbling rather than natural crystal growth.

Identified August 15, 2026More mineral →

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Physical properties

Formation & geological history

Jasper forms when silica-rich fluids replace or cement sediment and volcanic material, with iron oxides producing the brown coloration. Deposits occur in many geologic ages, commonly in volcanic and sedimentary terrains.

Uses & applications

Used for cabochons, beads, carvings, worry stones, and decorative objects; its toughness makes it suitable for everyday jewelry and lapidary work.

Geological facts

Jasper is a variety of chalcedony or microcrystalline quartz, though the term is also used broadly for opaque silica-rich rocks. Color and pattern depend largely on iron, clay, and other mineral inclusions.

Field identification & locations

Identify it by its opacity, even earthy color, glassy-to-waxy surface, and resistance to scratching by steel; it should not fizz in dilute acid. Common sources include the western United States, Madagascar, Brazil, India, and Australia.