mineral

Carnelian

Carnelian (SiO2, Silicon Dioxide with Iron Oxide impurities)

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

Identified February 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica in cavities and veins within igneous or sedimentary rocks; most common in volcanic environments. Its distinct color is caused by iron oxide impurities. It found in deposits ranging from ancient Neogene to modern formations.

Uses & applications

Primarily used in jewelry (beads, cabochons, intaglios), ornamental carvings, and historical talismans. It is also a popular specimen for rock tumbling and collector display.

Geological facts

Carnelian was used by ancient Egyptians for jewelry and amulets, as they believed it offered protection. In Rome, it was often used for signet rings because hot wax does not stick to it.

Field identification & locations

Identify by its translucent orange-red hue and smooth waxy luster. Common locations include Brazil, India, Madagascar, and Uruguay. In the field, look for nodules in riverbeds or volcanic gravel.

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