gemstone

Carnelian

Silicon dioxide (chalcedony variety), SiO2

Hardness: 6.5 to 7 on the Mohs scale. Color: Orange, reddish-orange, brownish-red to pinkish. Luster: Vitreous to waxy. Crystal structure: Trigonal (microcrystalline quartz). Cleavage: None, exhibits conchoidal fracture. Specific gravity: 2.58 to 2.64.

Hardness: 6
Color: Orange, reddish-orange, brownish-red to pinkish
Luster: Vitreous to waxy

Identified August 2, 2026More gemstone →

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Physical properties

Formation & geological history

Forms in low-temperature environments such as cavities in volcanic and sedimentary rocks where silica-rich groundwater deposits microcrystalline quartz, often colored by iron oxide impurities.

Uses & applications

Widely used in jewelry, cabochons, beads, and carved into signet rings and talismans since antiquity.

Geological facts

Carnelian was highly prized in ancient civilizations like Ancient Egypt, where it was associated with the goddess Isis and used in amulets for the afterlife. Its color comes from dispersed iron oxide.

Field identification & locations

Can be identified by its distinctive translucent orange-to-red color and waxy luster. Commonly found in Brazil, India, Uruguay, and Madagascar.

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