mineral

Carnelian (Chalcedony)

Cryptocrystalline Quartz (SiO2) with Iron Oxide impurities

Hardness: 6.5-7 (Mohs scale); Color: Brownish-red to orange-red; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.58-2.64

Hardness: 6
Color: Brownish-red to orange-red
Luster: Vitreous to waxy

Identified March 28, 2026More mineral →

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Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Brownish-red to orange-red; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.58-2.64

Formation & geological history

Formed in volcanic and sedimentary environments through the deposition of silica-rich groundwater in cavities or veins. Its reddish color comes from iron oxide (hematite) impurities. It can be found in formations ranging from recent to hundreds of millions of years old.

Uses & applications

Primarily used in jewelry making (beads, cabochons, semiprecious stones), decorative carving, and as a popular specimen for rock tumbling and metaphysical collections.

Geological facts

In antiquity, Carnelian was widely used for Roman signet rings and Egyptian amulets, as it does not stick to hot wax. It was believed to provide courage in battle and protection from the 'evil eye'.

Field identification & locations

Identify in the field by its waxy luster, translucency when held to light, and smooth conchoidal (shell-like) fracture. Commonly found in Brazil, India, Uruguay, and the United States (notably Oregon and Washington).

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