mineral

Carnelian

Carnelian (Silica/Quartz Variety), SiO2 with Fe2O3 impurities

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs); Color: Orange, reddish-brown, or translucent red; Luster: Vitreous to waxy; Crystal Structure: Trigonal (cryptocrystalline); Cleavage: None; Specific Gravity: 2.58-2.64

Hardness: 6
Color: Orange, reddish-brown, or translucent red
Luster: Vitreous to waxy

Identified July 1, 2026More mineral →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Orange, reddish-brown, or translucent red; Luster: Vitreous to waxy; Crystal Structure: Trigonal (cryptocrystalline); Cleavage: None; Specific Gravity: 2.58-2.64

Formation & geological history

Formed primarily in volcanic environments where silica-rich groundwater percolates through cavities in igneous rock, precipitating chalcedony at low temperatures over millions of years. The color is derived from iron oxide impurities.

Uses & applications

Extensively used in lapidary work for cabochons, beads, intaglios, and jewelry. Historically used for signet rings and wax seals due to its waxy luster which prevents hot wax from sticking.

Geological facts

Ancient Egyptians called carnelian "the setting sun" and believed it could protect the soul in the afterlife. It was also used by Roman and Greek civilizations for engraving seals and amulets.

Field identification & locations

Identify by its translucent, waxy appearance and orange-red hue. Commonly found in Brazil, India, Madagascar, and Uruguay. In the field, look for nodules with a smooth, conchoidal fracture.