Mineral

Carnelian Agate

Silicon Dioxide (SiO2) - variety of Chalcedony

Hardness: 6.5-7 on Mohs scale; Color: Translucent orange, red, and brownish-red; Luster: Vitreous to waxy; Crystal Structure: Trigonal (Microcrystalline); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.58–2.64

Hardness: 6
Color: Translucent orange, red, and brownish-red
Luster: Vitreous to waxy

Identified March 20, 2026More mineral →

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Physical properties

Formation & geological history

Formed in volcanic and sedimentary environments through the deposition and precipitation of silica-rich groundwater. Its red-orange color is caused by iron oxide (hematite) impurities. It can be found in rocks ranging from the Eocene to the Cretaceous periods.

Uses & applications

Commonly used for lapidary work, jewelry (beads, cabochons), and engraved seals (intaglios). It is also highly popular in the metaphysical and gem collecting community.

Geological facts

In ancient times, carnelian was believed to have protective properties. The legendary 'Seal of Muhammad' was said to be an engraved carnelian set in silver. It has been used for jewelry for over 4,500 years, dating back to ancient Sumerian and Egyptian civilizations.

Field identification & locations

Identify in the field by its waxy luster, translucency when held to light, and lack of visible crystalline structure. Common locations include Brazil, India, Madagascar, Uruguay, and various riverbeds in the Pacific Northwest of the USA. Collectors look for high translucency and uniform color.

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