gemstone

Tumbled orange-red translucent stone, likely carnelian

Carnelian, a chalcedony variety of microcrystalline quartz (SiO₂)

AI-generated identification · may be incorrect

Typically Mohs hardness 6.5–7, vitreous to waxy luster, orange-red to brown color, translucent edges, and no visible cleavage; its cryptocrystalline quartz structure gives a smooth fracture and polish.

Identified September 20, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater deposits chalcedony in cavities and fractures, with iron oxides producing the orange-red color. It occurs in volcanic and sedimentary environments, commonly ranging from Paleozoic to Cenozoic deposits.

Uses & applications

Used for beads, cabochons, carvings, seals, and inexpensive jewelry; polished pieces are popular ornamental stones and lapidary material.

Geological facts

The color may be intensified by heating or dyeing, so strongly uniform red-orange material may be treated rather than naturally colored.

Field identification & locations

Common sources include India, Brazil, Uruguay, Madagascar, and the United States. Field clues are translucency, waxy luster, conchoidal fracture, and inability to scratch it with a steel knife; definitive identification requires testing.