mineral

Carnelian (Chalcedony)

Silicon Dioxide (SiO2) with Iron Oxide impurities

Hardness: 6.5-7.0 (Mohs scale), Color: Reddish-orange to brownish-red, Luster: Vitreous to waxy, Crystal Structure: Trigonal (microcrystalline), Cleavage: None/Conchoidal fracture, Specific Gravity: 2.58-2.64

Hardness: 6

Identified July 3, 2026More mineral →

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Physical properties

Formation & geological history

Formed in volcanic cavities or sedimentary environments where silica-rich fluids deposit at low temperatures. Its color is derived from iron oxide inclusions. Specimens often date back to the Tertiary or Quaternary periods.

Uses & applications

Predominantly used in jewelry, lapidary arts, tumbled pocket stones, and decorative carvings. Historically used for signet rings and cylinder seals.

Geological facts

Carnelian was highly prized in ancient Egypt and Mesopotamia. It was believed to protect the wearer and was one of the stones used in the Breastplate of Aaron.

Field identification & locations

Identified by its translucent to semi-opaque orange-red hue and smooth waxy texture. Commonly found in Brazil, India, Uruguay, Madagascar, and the USA (Oregon/Washington). Collectors should check for even color and translucency.

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