mineral

Carnelian (Red Chalcedony)

Silicon Dioxide (SiO2) - variety of Chalcedony

AI-generated identification · may be incorrect

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

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

Identified April 10, 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: Hexagonal (trigonal) microcrystalline; Cleavage: None; Specific Gravity: 2.58-2.64.

Formation & geological history

Formed from silica-rich groundwater percolating through volcanic or sedimentary rock cavities. Its red color is caused by impurities of iron oxide (hematite). Found in deposits primarily in volcanic environments.

Uses & applications

Used extensively in jewelry (beads, cabochons, rings), decorative carvings, and seal stones. Historically used for signet rings because hot wax does not stick to it.

Geological facts

Carnelian was highly prized in ancient Egypt, where it was linked to the sun god Ra. It has been used as a gemstone for over 4,500 years and was often buried with the dead as a protective amulet.

Field identification & locations

Identify in the field by its translucent orange-to-red color and conchoidal (shell-like) fracture. Commonly found in India, Brazil, Uruguay, and Madagascar. Collectors should look for even saturation of color and high translucency.