mineral

Carnelian

Carnelian (Silicon Dioxide - SiO2)

Hardness: 6.5–7 (Mohs scale); Color: Orangey-red, brownish-red; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.58–2.64

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

Identified June 21, 2026More mineral →

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Physical properties

Hardness: 6.5–7 (Mohs scale); Color: Orangey-red, brownish-red; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific Gravity: 2.58–2.64

Formation & geological history

Formed through the deposition of silica in cavities and veins of volcanic rock (igneous) or sedimentary rocks. The orange-red color is caused by iron oxide impurities. It occurs globally in geological settings ranging from Ancient volcanic basalt to modern river deposits.

Uses & applications

Predominantly used in jewelry (cabochons, beads), decorative carvings, wax seal stamps, and as a popular semi-precious stone for gem collectors and spiritual practitioners.

Geological facts

Carnelian has been used for over 4,500 years. Ancient Egyptians called it 'the setting sun' and used it in the burial of pharaohs to assist with the journey to the afterlife. It was also commonly used in Roman signet rings for sealing documents because hot wax does not stick to it.

Field identification & locations

Identify by its translucent waxy appearance and orange color. It lacks the banding of typical agate but shares its toughness. Often found in riverbeds or gravel deposits near volcanic areas (e.g., Brazil, India, Uruguay). It is much harder than glass and cannot be scratched by a steel knife.