mineral

Carnelian

Carnelian (SiO2 - Silicon Dioxide with Iron Oxide impurities)

Hardness: 6.5-7 on Mohs scale; Color: Translucent orange to reddish-brown; Luster: Vitreous to waxy; Crystal Structure: Hexagonal/Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58–2.64

Hardness: 6
Color: Translucent orange to reddish-brown
Luster: Vitreous to waxy

Identified March 20, 2026More mineral →

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Physical properties

Formation & geological history

Formed by the precipitation of silica from groundwater into cavities (vugs) of igneous basalt or sedimentary rocks. The characteristic red/orange 'carnelian' color develops over time as iron impurities oxidize.

Uses & applications

Primarily used in jewelry (cabochons, beads), decorative lapidary carvings, seal stones, and as a popular semi-precious stone for gemstone collectors.

Geological facts

Carnelian has been used for over 4,500 years; ancient Romans and Greeks used it for signet rings because hot wax does not stick to it. It was also found in the decor of the Taj Mahal.

Field identification & locations

Identify by its translucent, 'fleshy' orange glow when held to a light source. Found globally with major deposits in India, Brazil, and Uruguay. Field collectors look for the distinctive waxy luster in riverbeds or volcanic outcrops.

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