mineral

Carnelian (Orange Chalcedony)

Silicon Dioxide (SiO2) with iron oxide impurities

Hardness: 6.5-7 (Mohs scale); Color: Orange to reddish-brown; Luster: Vitreous to waxy; Crystal structure: Hexagonal (Trigonal), cryptocrystalline; Cleavage: None; Specific gravity: 2.58–2.64

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

Identified April 6, 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: Hexagonal (Trigonal), cryptocrystalline; Cleavage: None; Specific gravity: 2.58–2.64

Formation & geological history

Forms in low-temperature hydrothermal environments where silica-rich groundwater percolates through cavities in volcanic rocks. The orange color is caused by the presence of iron oxide (hematite) impurities which can be enhanced by heat treatment.

Uses & applications

Commonly used as a gemstone in jewelry (cabochons, beads), decorative carvings, and seal stones. It is also a popular specimen for metaphysical collections.

Geological facts

Carnelian was famously used in Ancient Egypt for scarabs and amulets, often associated with the goddess Isis. In Roman times, it was frequently used for signet rings because hot wax does not stick to the stone.

Field identification & locations

Identify in the field by its translucent appearance, waxy luster, and lack of visible crystals. It is commonly found in Brazil, India, Uruguay, Madagascar, and parts of the United States (like Washington and Oregon).

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