mineral

Tumbled brown chalcedony (possibly carnelian or jasper)

Microcrystalline quartz, SiO₂; likely iron-stained chalcedony

AI-generated identification · may be incorrect

Opaque to translucent brown-orange, with a dull to waxy luster and rounded tumbled surface. Quartz hardness is Mohs 7, no cleavage, cryptocrystalline structure, and specific gravity about 2.60–2.65.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, later acquiring brown-red color from iron oxides. The image cannot establish its geological age; chalcedony occurs in volcanic, sedimentary, and hydrothermal environments.

Uses & applications

Used as a lapidary stone for cabochons, beads, carvings, and decorative objects; attractive pieces have modest jewelry and collecting value.

Geological facts

Its exact identity may be carnelian if translucent reddish-orange, or jasper if more opaque and strongly patterned. Tumbled stones commonly obscure diagnostic natural textures.

Field identification & locations

Common sources include Brazil, Uruguay, India, Madagascar, Mexico, and the western United States. A steel file should not easily scratch it; streak, hardness, and translucency tests help distinguish quartz varieties.