mineral

Carnelian (Orange Chalcedony)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Orange to reddish-brown; Luster: Waxy to vitreous; Crystal Structure: Hexagonal (cryptocrystalline); Cleavage: None; Fracture: Conchoidal; Specific Gravity: 2.58-2.64.

Hardness: 6
Color: Orange to reddish-brown
Luster: Waxy to vitreous

Identified June 30, 2026More mineral →

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Physical properties

Formation & geological history

Formed in low-temperature hydrothermal environments where silica-rich fluids deposit in volcanic rock cavities or sedimentary layers. The orange color is due to iron oxide impurities (hematite).

Uses & applications

Primarily used as a gemstone in jewelry, beads, cabochons, and decorative carvings. Historically used for signet rings and seals because wax does not stick to it.

Geological facts

Ancient Egyptians called carnelian the sunset stone and believed it held powerful protective properties. It is a variety of chalcedony, which is a microcrystalline form of quartz.

Field identification & locations

Identify by its orange-red translucency and waxy surface. Found worldwide, with major deposits in Brazil, India, Madagascar, and Uruguay. In the field, look for nodules with a smooth, weathered exterior.

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Mineral

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Mineral/Rock

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