mineral

Tumbled brown jasper or chalcedony

Microcrystalline quartz (SiO₂), likely iron-stained jasper/chalcedony

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; opaque to slightly translucent, brown to olive-brown with cloudy yellow patches and a smooth glassy/waxy luster. It has a cryptocrystalline quartz structure and no visible cleavage; specific gravity is about 2.6.

Identified August 30, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids fill cavities or replace volcanic sediment, with iron oxides producing the brown coloration. The specimen is tumbled and polished, so its precise geological age and source cannot be determined from the image.

Uses & applications

Used as a decorative stone, worry stone, cabochon, beads, and small carvings; polished jasper is primarily valued for appearance rather than rarity.

Geological facts

Jasper is an opaque variety of chalcedony, while chalcedony is translucent to semi-translucent microcrystalline quartz. Brown coloration commonly reflects hematite, goethite, or other iron-bearing impurities.

Field identification & locations

Identify it by its very smooth polish, waxy/glassy surface, quartz-like hardness, and opaque earthy pattern; it should resist scratching by a steel knife. Common sources include Brazil, India, Madagascar, Australia, and the western United States.