mineral

Carnelian

Carnelian (Cryptocrystalline Quartz, SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs scale); Color: Orange to reddish-brown; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (trigonal microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.64

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

Identified July 18, 2026More mineral →

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Physical properties

Formation & geological history

Forms primarily as a secondary mineral in volcanic rock cavities or sedimentary environments through the deposition of silica from groundwater. The orange-red color comes from impurities of iron oxide (hematite).

Uses & applications

Widely used for jewelry (beads, cabochons, rings), seal stones, carvings, and as a popular tumbled stone for collectors.

Geological facts

Ancient Romans used carnelian for signet rings because hot wax does not stick to it. It has been used in jewelry for over 4,500 years, dating back to Ur and ancient Egypt.

Field identification & locations

Identify by its translucent, waxy finish and even orange-to-red color. It can be found in India, Brazil, Uruguay, and Madagascar. Collectors often look for uniform color and transparency.