gemstone

Tumbled carnelian

Carnelian, a translucent orange-red variety of chalcedony (microcrystalline quartz, SiO₂)

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; orange, red, and brown coloration from iron oxides; waxy to vitreous luster, cryptocrystalline structure, no visible cleavage, and specific gravity about 2.6.

Identified September 22, 2026More gemstone →

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Physical properties

Mohs hardness 6.5–7; orange, red, and brown coloration from iron oxides; waxy to vitreous luster, cryptocrystalline structure, no visible cleavage, and specific gravity about 2.6.

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, with iron producing the color; commonly associated with volcanic rocks and ancient sedimentary deposits, ranging from Paleozoic to younger formations.

Uses & applications

Used for beads, cabochons, carvings, seals, and ornamental objects; polished tumbled pieces are inexpensive and popular in jewelry and collections.

Geological facts

Color may intensify when heated, a traditional treatment sometimes applied to pale chalcedony. Carnelian was prized in ancient Egypt, Greece, Rome, and Mesopotamia.

Field identification & locations

Identify it by its warm translucent orange-red color, smooth waxy polish, and lack of cleavage; common sources include India, Brazil, Uruguay, Madagascar, and Germany. Natural carnelian usually shows subtle color zoning rather than perfectly uniform dye saturation.