mineral

Carnelian Agate

Silicon Dioxide (SiO2) - Variety of Chalcedony

Hardness: 6.5-7 on Mohs scale. Color: Orange to reddish-brown (caused by iron oxide). Luster: Vitreous to waxy. Crystal Structure: Hexagonal (Trigonal), microcrystalline. Cleavage: None (Conchoidal fracture). Specific Gravity: 2.58-2.64.

Hardness: 6
Color: Orange to reddish-brown (caused by iron oxide)
Luster: Vitreous to waxy

Identified March 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica from groundwater in the cavities of igneous rocks, particularly volcanic lavas. The banding is the result of rhythmic precipitation of the silica over thousands to millions of years.

Uses & applications

Primarily used as a gemstone in jewelry (beads, cabochons, rings), decorative carvings, and as a popular focus for crystal collectors and lapidary artists.

Geological facts

Carnelian has been used for over 4,000 years. Ancient Romans used it for signet rings and wax seals because hot wax does not stick to it. It was also highy valued in Ancient Egypt as a symbol of life and the setting sun.

Field identification & locations

Identify in the field by its distinctive waxy luster, translucency, and warm orange banding. Common locations include Brazil, India, Madagascar, and Germany. Look for it in riverbeds or within basaltic host rocks.

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