mineral

Carnelian

Carnelian (SiO2)

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

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

Identified May 9, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in low-temperature hydrothermal environments where silica-rich groundwater fills cavities in volcanic or sedimentary rocks, often found as nodules or in geodes.

Uses & applications

Primarily used as a gemstone for jewelry, cabochons, beads, and as an ornamental stone in lapidary arts like intaglios and cameos.

Geological facts

Carnelian was highly prized in ancient civilizations; the Romans used it for signet rings because hot wax does not stick to it, and it was used in Egypt as the 'blood of Isis' to represent rejuvenation.

Field identification & locations

Identify in the field by its distinct translucent orange hue and waxy luster. Common locations include Brazil, India, Madagascar, and Uruguay. Look for it along riverbeds or eroded volcanic landscapes.