gemstone

Polished jasper or jasper-like chalcedony

Microcrystalline quartz (SiO₂), likely iron-oxide-bearing jasper

AI-generated identification · may be incorrect

Opaque to slightly translucent, rounded and highly polished, with mustard-yellow, reddish-brown, and cream mottling; vitreous-to-waxy luster and no visible cleavage. Quartz hardness is about 6.5–7 Mohs; specific gravity approximately 2.6.

Identified September 12, 2026More gemstone →

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Physical properties

Formation & geological history

Jasper forms when silica-rich fluids replace or cement volcanic, sedimentary, or hydrothermal material, with iron oxides producing the red-yellow colors. The specimen appears tumbled or cabochon-polished; its precise geological age cannot be determined from the image.

Uses & applications

Used for lapidary cabochons, beads, carvings, worry stones, and decorative objects; generally an affordable ornamental gemstone.

Geological facts

The yellow coloration commonly reflects goethite or limonite, while red-brown areas usually contain hematite. Similar appearances can occur in brecciated jasper, mookaite, or dyed chalcedony.

Field identification & locations

Identify it by its opaque silica body, mottled iron-rich colors, glassy polish, and resistance to scratching; it should not be scratched by a steel knife. Jasper is widespread, including deposits in Australia, India, Madagascar, Brazil, South Africa, and the western United States.