mineral

Carnelian

Carnelian (SiO2, Silicon Dioxide with Iron Oxide impurities)

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs); Color: Reddish-orange, brownish-red; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Hexagonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.64

Hardness: 6
Color: Reddish-orange, brownish-red
Luster: Vitreous to waxy

Identified June 24, 2026More mineral →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Reddish-orange, brownish-red; Luster: Vitreous to waxy; Crystal Structure: Trigonal/Hexagonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.64

Formation & geological history

Formed in cavities and veins of volcanic and sedimentary rocks. The color is derived from iron oxide (hematite) impurities. It typically forms at low temperatures through the deposition of silica from groundwater.

Uses & applications

Used primarily in jewelry (cabochons, beads), decorative carvings, and as a collector's gemstone. Historically used for seal stones and amulets.

Geological facts

Carnelian has been used as a gemstone for over 4,500 years. Ancient Egyptians believed it helped spirits pass into the afterlife, and it was famously worn by Napoleon on his watch seal.

Field identification & locations

Identify by its translucent to semi-opaque red-orange color and lack of banding (unlike agate). Common in Brazil, India, Madagascar, and Uruguay. In the field, look for pebbles with a waxy luster in gravel deposits or volcanic host rocks.