mineral

Carnelian (a variety of Chalcedony)

Silicon Dioxide (SiO2) with iron oxide impurities

Hardness: 6.5-7 on the Mohs scale; Color: Reddish-brown, orange, or amber; Luster: Vitreous to waxy; Crystal structure: Hexagonal (trigonal) cryptocrystalline; Cleavage: None; Specific Gravity: 2.58–2.64.

Hardness: 6
Color: Reddish-brown, orange, or amber
Luster: Vitreous to waxy

Identified July 1, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica from groundwater in volcanic rock cavities or sedimentary environments. The orange hue is caused by iron oxide (limonite or hematite) impurities. It can be found in various geological settings across eras.

Uses & applications

Primarily used in jewelry (beads, cabochons), lapidary art, and intaglio carving. Historically used for signet rings and amulets.

Geological facts

Carnelian was highly prized in ancient times; it was used in Egypt for its protective properties and found in the tombs of Pharaohs. It was also commonly used in Ancient Rome for signet rings because hot wax does not stick to it.

Field identification & locations

Identify in the field by its waxy luster, translucency, and warm orange-red color. It is commonly found in Brazil, India, Madagascar, and Uruguay. Collectors look for uniform color and high translucency.

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