mineral

Carnelian

Carnelian (Silicon Dioxide - SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Orange to reddish-brown; Luster: Vitreous to waxy; Crystal structure: Trigonal (cryptocrystalline chalcedony); Cleavage: None; Specific Gravity: 2.58-2.64.

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

Identified April 4, 2026More mineral →

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Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Orange to reddish-brown; Luster: Vitreous to waxy; Crystal structure: Trigonal (cryptocrystalline chalcedony); Cleavage: None; Specific Gravity: 2.58-2.64.

Formation & geological history

Formed through the deposition of silica from groundwater into cavities (vugs) within volcanic (igneous) rocks or through low-temperature hydrothermal processes. It gets its color from iron oxide impurities.

Uses & applications

Primarily used in jewelry (cabochons and beads), decorative carvings, and as a semi-precious collector's stone. Historically used for signet rings and seals because hot wax does not stick to it.

Geological facts

Carnelian has been used for over 4,500 years; ancient Egyptians believed it had protective properties and used it extensively in funerary amulets. It is the semi-precious variety of chalcedony.

Field identification & locations

Identify by its translucency and uniform orange-to-red hue without the distinct banding seen in agates. Commonly found in Brazil, India, Uruguay, and Madagascar. Collectors should look for even color saturation.