gemstone

Carnelian

SiO2 (Silicon Dioxide)

Hardness: 6.5-7.0 on the Mohs scale. Color: Orangish-red to deep reddish-brown. Luster: Vitreous to waxy. Crystal Structure: Hexagonal (trigonal) microcrystalline. Cleavage: None. Specific Gravity: 2.58-2.64.

Hardness: 6
Color: Orangish-red to deep reddish-brown
Luster: Vitreous to waxy

Identified July 13, 2026More gemstone →

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Physical properties

Formation & geological history

Formed as a cryptocrystalline variety of quartz (chalcedony) in volcanic rocks or through hydrothermal activity where silica-rich fluids deposit in cavities. The color is derived from iron oxide impurities.

Uses & applications

Primarily used as a gemstone in jewelry, beads, and cabochons. Historically used for making signet rings and cylinder seals due to its lack of adhesion to hot wax.

Geological facts

Carnelian has been used for thousands of years, dating back to Neolithic times and Ancient Egypt. It was believed by many ancient cultures to represent the setting sun and was associated with courage and vitality.

Field identification & locations

Identify by its translucent to semi-opaque reddish-orange color and lack of banding (which would make it an agate). It is commonly found in Brazil, India, Uruguay, and Madagascar.