gemstone

Polished carnelian

Chalcedony (microcrystalline quartz), SiO₂; iron-bearing variety

AI-generated identification · may be incorrect

Typically Mohs 6.5–7, translucent orange-red to brown, with waxy-to-glassy luster and no visible cleavage; cryptocrystalline quartz has fibrous microstructure. This small tumbled stone shows brown-orange coloration and mottled translucency.

Identified August 16, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures in volcanic rocks; iron oxides produce the red-orange color. Deposits are generally young to ancient, commonly associated with Cenozoic and older volcanic terrains.

Uses & applications

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

Geological facts

Carnelian is a traditional variety of chalcedony whose color may be enhanced by heating. Its name is linked to Latin carnis, “flesh,” describing its warm reddish hue.

Field identification & locations

Identify by its orange-red/brown color, smooth waxy polish, translucency, and lack of cleavage; it should resist scratching by steel but be scratched by quartz. Common sources include India, Brazil, Uruguay, Madagascar, and Botswana.