gemstone

Tumbled carnelian

Carnelian, a reddish-orange variety of microcrystalline quartz (SiO₂), commonly colored by dispersed iron oxides

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent red-brown to orange, with a waxy or glassy luster and no visible crystal faces. Quartz has a trigonal crystal structure, but the specimen is cryptocrystalline and typically lacks cleavage; specific gravity is about 2.60–2.65.

Identified September 7, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich fluids deposit chalcedony in cavities, fractures, or volcanic vesicles, with iron producing the red coloration; many examples formed during Cenozoic or older volcanic activity. The smooth shape indicates human tumbling and polishing.

Uses & applications

Used for beads, cabochons, carvings, seals, and inexpensive jewelry; also popular as a decorative and metaphysical collecting stone.

Geological facts

Carnelian is a member of the chalcedony family and may fade or change color with prolonged heating or sunlight. Natural color commonly shows uneven red-orange zoning.

Field identification & locations

Look for translucent edges, warm red-orange color, waxy luster, and quartz-like hardness; it commonly occurs in India, Brazil, Uruguay, Madagascar, and Germany. A steel file should not easily scratch it.