mineral

Carnelian Agate

Silicon Dioxide (SiO2) - Chalcedony variety

Hardness: 6.5 - 7 on the Mohs scale. Color: Orange to reddish-brown with white or clear banding. Luster: Vitreous to waxy. Crystal Structure: Trigonal (cryptocrystalline). Cleavage: None (conchoidal fracture). Specific Gravity: 2.58–2.64.

Hardness: 6
Color: Orange to reddish-brown with white or clear banding
Luster: Vitreous to waxy

Identified January 11, 2026More mineral →

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Physical properties

Formation & geological history

Formed by the deposition of silica from groundwater into cavities of igneous rocks (usually basalt). The orange color is caused by impurities of iron oxide (hematite). Occurs in geological layers ranging from Jurassic to recent eras.

Uses & applications

Commonly used in the jewelry industry for beads, cabochons, and signet rings. Also used for decorative carvings, palm stones for collectors, and historically for wax seals because hot wax does not stick to it.

Geological facts

Carnelian has been used for over 4,500 years; it was highly prized by Ancient Egyptians who called it the 'setting sun.' In Roman times, it was frequently used for intaglio engraved gems for signet rings.

Field identification & locations

Identify in the field by its distinct translucent 'waxy' appearance and the presence of fine, concentric or parallel banding (chalcedony bands). Often found in riverbeds or volcanic regions like those in Brazil, India, Madagascar, and Uruguay. Look for stones that glow when held up to a light source.

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