gemstone

Carnelian (orange chalcedony)

Cryptocrystalline quartz, SiO₂; orange variety of chalcedony

AI-generated identification · may be incorrect

Typically translucent orange to reddish-orange, with a vitreous-to-waxy luster and no visible crystal faces; Mohs hardness 6.5–7, conchoidal fracture, and specific gravity about 2.60–2.65. The specimen appears tumbled or naturally rounded, though its small size and surface reflections limit certainty.

Identified August 20, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, later acquiring orange coloration from iron oxides. Deposits occur in volcanic rocks and sedimentary gravels, commonly ranging from Cenozoic to older geological ages.

Uses & applications

Used for beads, cabochons, carvings, seals, and inexpensive jewelry; polished pieces are also popular mineral specimens.

Geological facts

Carnelian is a translucent variety of chalcedony, itself a microcrystalline form of quartz. Its color can be enhanced by heating or dyeing, so strong uniform color may indicate treatment.

Field identification & locations

Common localities include India, Brazil, Uruguay, Madagascar, Germany, and the United States. Identification relies on hardness, waxy luster, translucency, and resistance to scratching by steel; it should not scratch glass easily if heavily weathered or coated.