mineral

Tumbled orange chalcedony or carnelian

Cryptocrystalline quartz, SiO₂; likely carnelian variety

AI-generated identification · may be incorrect

Small, rounded, polished orange-brown pebble with translucent edges and a waxy to vitreous luster. Quartz hardness is about 7 Mohs; no visible cleavage, conchoidal fracture, and specific gravity near 2.60–2.65.

Identified August 29, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, later acquiring orange coloration from finely dispersed iron oxides. The exact geological age cannot be determined from the photograph; deposits occur in volcanic and sedimentary terrains worldwide.

Uses & applications

Used for beads, cabochons, carvings, and inexpensive jewelry; tumbled pieces are common collectibles and decorative stones.

Geological facts

Carnelian is orange to red chalcedony, while paler or less strongly colored material may be called orange chalcedony. Color can be naturally enhanced or heat-treated.

Field identification & locations

Likely identification requires a hardness test: it should scratch ordinary glass, while a steel knife should not scratch it. Common sources include India, Brazil, Uruguay, Madagascar, and the United States.