mineral

Carnelian

Carnelian (Silicon Dioxide, SiO2)

Hardness: 6.5-7 Mohs; Color: Orange, reddish-brown, brownish-red; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (trigonal); Cleavage: None; Specific Gravity: 2.58-2.64

Hardness: 6
Color: Orange, reddish-brown, brownish-red
Luster: Vitreous to waxy

Identified June 18, 2026More mineral →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Orange, reddish-brown, brownish-red; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (trigonal); Cleavage: None; Specific Gravity: 2.58-2.64

Formation & geological history

Formed as a microcrystalline variety of chalcedony through the deposition of silica in gas cavities of volcanic rocks or in sedimentary environments. Its color comes from iron oxide impurities.

Uses & applications

Primarily used in jewelry for cabochons and beads, as well as in ornamental carvings, intaglios, and seal stones.

Geological facts

Carnelian has been used for thousands of years; it was highly prized in Ancient Egypt for amulets and in Rome for signet rings because hot wax does not stick to it.

Field identification & locations

Identify by its translucent orange/red color and waxy luster. Common locations include Brazil, India, Madagascar, and Uruguay. Collectors should look for uniform color and high translucency.