mineral

Carnelian

SiO2 (Silicon Dioxide with Iron Oxide impurities)

Hardness: 6.5-7 on Mohs scale; Color: Reddish-orange to brownish-red; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.59-2.61.

Hardness: 6
Color: Reddish-orange to brownish-red
Luster: Vitreous to waxy

Identified June 12, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Reddish-orange to brownish-red; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.59-2.61.

Formation & geological history

Formed through the deposition of silica from groundwater in the cavities of igneous rocks, particularly volcanic lavas. The red hue comes from iron oxide (hematite) impurities.

Uses & applications

Primarily used in jewelry, lapidary arts for cabochons and beads, and historical signet rings/seals due to its property of not sticking to hot wax.

Geological facts

Carnelian was highly prized in ancient Egypt, where it was thought to grant protection in the afterlife and was often buried with mummies. It was also widely used by Babylonian and Roman civilizations for engraved seals.

Field identification & locations

Identified by its distinctive translucency and warm orange-red color. Commonly found in Brazil, India, Madagascar, and Uruguay. Field collectors look for the waxy luster and conchoidal fracture patterns typical of chalcedony.

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