mineral

Carnelian

Carnelian (Chert/Chalcedony) - SiO2

Hardness: 6.5-7 on Mohs scale; Color: Orange-red to brownish-red; Luster: Waxy to vitreous; Crystal structure: Hexagonal (Trigonal); Cleavage: None; Specific gravity: 2.58-2.64.

Hardness: 6
Color: Orange-red to brownish-red
Luster: Waxy to vitreous

Identified May 25, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Orange-red to brownish-red; Luster: Waxy to vitreous; Crystal structure: Hexagonal (Trigonal); Cleavage: None; Specific gravity: 2.58-2.64.

Formation & geological history

Formed in the cavities of volcanic rocks or sedimentary environments through the deposition of silica from groundwater at low temperatures. Its orange hue comes from iron oxide impurities.

Uses & applications

Primarily used for semi-precious jewelry (beads, cabochons), carvings, and seals. Highly valued as an ornamental stone and by mineral collectors.

Geological facts

In ancient times, carnelian was believed to protect the wearer from bad luck and provide courage. It was one of the first stones used for cylinder seals in Mesopotamia and ancient Egypt.

Field identification & locations

Identify by its translucent reddish-orange color and waxy luster. Common in Brazil, India, Uruguay, and Madagascar. In the field, look for nodules with a smooth, almost greasy surface texture when wet.