mineral

Carnelian Agate

Silicon Dioxide (SiO2) - Carnelian variety of Chalcedony

Hardness: 6.5–7 on the Mohs scale; Color: Reddish-orange to brownish-red; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.58–2.64.

Hardness: 6
Color: Reddish-orange to brownish-red
Luster: Vitreous to waxy

Identified April 9, 2026More mineral →

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Physical properties

Formation & geological history

Formed in volcanic cavities (vugs) or silica-rich sedimentary environments. The red/orange color is caused by the presence of iron oxide (hematite) impurities. Most specimens are millions of years old, often found in Cenozoic basalts.

Uses & applications

Commonly used in jewelry (beads, cabochons, rings), decorative ornaments, and widely collected as pocket stones. Historically used for signet rings and wax seals because hot wax does not stick to it.

Geological facts

In ancient times, carnelian was believed to protect the wearer from bad luck and promote courage. It was one of the first stones used by ancient civilizations for tools and adornment, dating back to 4th millennium BC.

Field identification & locations

Identify by its waxy luster, translucency when held to light, and lack of visible crystal grains. Found in Brazil, India, Uruguay, and parts of the United States like Oregon and Washington.

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