mineral

Carnelian

Carnelian (variety of Chalcedony, SiO2)

Hardness: 6.5–7 on Mohs scale; Color: Red-orange to brownish-red due to iron oxide impurities; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58–2.64.

Hardness: 6
Color: Red-orange to brownish-red due to iron oxide impurities
Luster: Vitreous to waxy

Identified March 25, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica in cavities of igneous rocks, often at low temperatures. Its coloration is derived from hematite (iron oxide) inclusions. It can be found in volcanic rocks ranging from prehistoric to modern geological ages.

Uses & applications

Primarily used in jewelry for cabochons and beads, as well as in the production of cameos and intaglios. Historically used for seal stones and decorative carvings.

Geological facts

Carnelian was highly prized in Ancient Egypt where it was believed to represent the blood of Isis. It was also used by Roman senators in signet rings because hot wax does not stick to its smooth surface.

Field identification & locations

Identify in the field by its translucent warm orange hue and lack of visible crystals. It is commonly found in Brazil, India, Uruguay, and Madagascar. Collectors should look for even color saturation and a waxy surface texture.