mineral

Carnelian (Chalcedony)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Reddish-orange to brownish-red; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.59-2.61

Hardness: 6
Color: Reddish-orange to brownish-red
Luster: Waxy to vitreous

Identified June 11, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Reddish-orange to brownish-red; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.59-2.61

Formation & geological history

Formed through the deposition of silica from groundwater in the cavities of igneous rocks, particularly volcanic lavas. The reddish color is due to impurities of iron oxide (hematite).

Uses & applications

Primarily used in jewelry as cabochons, beads, and pendants. Historically used for seals and signet rings.

Geological facts

Carnelian was highly prized in ancient Egypt and Rome. It is mentioned in archaeological records dating back over 4,000 years and was often buried with the dead to assist them in the afterlife.

Field identification & locations

Identify in the field by its translucent waxy surface and uniform warm orange-red color. It is commonly found in India, Brazil, Uruguay, and Madagascar.