gemstone

Tumbled carnelian

Carnelian, a translucent chalcedony variety of quartz (SiO₂), colored mainly by iron oxides

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; orange-red to reddish brown, waxy to vitreous luster, cryptocrystalline quartz with no cleavage, conchoidal fracture, and specific gravity about 2.60. The rounded shape and polish indicate tumbling; surface pits may be natural or from treatment.

Identified August 19, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater deposits chalcedony in volcanic cavities, veins, or sedimentary fractures; iron oxidation produces the color. Deposits range from ancient Precambrian rocks to younger volcanic terrains.

Uses & applications

Used for beads, cabochons, carvings, seals, and ornamental objects; durable enough for jewelry. Common tumbled pieces typically have modest value.

Geological facts

Carnelian is traditionally associated with vitality and protection and was widely used for engraved seals in antiquity. Heating can intensify its orange-red color.

Field identification & locations

Common localities include India, Brazil, Uruguay, Madagascar, Germany, and the United States. Identify it by its orange translucency, quartz hardness, lack of cleavage, and inability to scratch glass only if sufficiently fresh and sharp.