gemstone

Tumbled orange chalcedony or carnelian

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony; orange-red varieties are called carnelian

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent orange, tan, and cream coloration with waxy to vitreous luster. Quartz has a trigonal crystal structure, but chalcedony is cryptocrystalline and shows no visible cleavage; specific gravity is about 2.6.

Identified September 1, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures in volcanic rocks, with iron oxides producing the orange color; commonly Cenozoic to older, depending on host rock.

Uses & applications

Used for beads, cabochons, carvings, and decorative objects; ordinary tumbled pieces have modest value.

Geological facts

Carnelian is a durable variety of chalcedony whose color ranges from yellow-orange to deep red-brown. Heating or dyeing may intensify its color.

Field identification & locations

Identify by its smooth waxy surface, translucent warm color, lack of cleavage, and inability to scratch glass only weakly or variably; quartz-rich gravels and volcanic regions commonly yield it. The image alone cannot distinguish natural carnelian from dyed chalcedony.