mineral

Carnelian

Carnelian (Silicon Dioxide, SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Red-orange to brownish-red; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.64

Hardness: 6
Color: Red-orange to brownish-red
Luster: Vitreous to waxy

Identified May 25, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Red-orange to brownish-red; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.64

Formation & geological history

Formed in volcanic cavities or sedimentary rocks through the deposition of silica from groundwater. The characteristic color comes from iron oxide impurities.

Uses & applications

Primarily used in jewelry (cabochons, beads), decorative carvings, and as a collector's gemstone. Historically used for seal stones and amulets.

Geological facts

In ancient times, carnelian was believed to protect the wearer and grant courage in battle. It was frequently used in Roman signet rings.

Field identification & locations

Identify by its translucent orange-red hue and waxy luster. Commonly found in Brazil, India, Uruguay, and Madagascar. Collectors look for uniform color and high translucency.