mineral

Tumbled banded jasper (probable)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide and other mineral inclusions

AI-generated identification · may be incorrect

Opaque, dark brown to black and tan, with irregular contrasting bands or brecciation; typically dull to waxy luster and no visible cleavage. Mohs hardness about 6.5–7; dense, fine-grained, and likely rounded by tumbling.

Identified August 22, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids replace or cement volcanic or sedimentary material, while iron oxides create the brown-black coloration; age depends on the source deposit. The photographed piece is human-polished/tumbled.

Uses & applications

Used as a lapidary stone for cabochons, beads, carvings, and decorative objects; attractive pieces are collected but are generally inexpensive.

Geological facts

Jasper is an opaque variety of chalcedony rather than a single mineral species; its patterns commonly reflect oxidation, brecciation, or repeated silica deposition.

Field identification & locations

Identify it by its opaque fine texture, hardness, waxy polish, and resistance to scratching by steel; quartz-rich jasper should scratch glass. Common sources include volcanic terrains worldwide, especially India, Madagascar, Brazil, Africa, and the western United States.