mineral

Chalcedony (Carnelian)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 Mohs; Color: Brownish-red to orange; Luster: Waxy to vitreous; Crystal structure: Trigonal (cryptocrystalline); Cleavage: None; Fracture: Conchoidal

Hardness: 6
Color: Brownish-red to orange
Luster: Waxy to vitreous

Identified July 6, 2026More mineral →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Brownish-red to orange; Luster: Waxy to vitreous; Crystal structure: Trigonal (cryptocrystalline); Cleavage: None; Fracture: Conchoidal

Formation & geological history

Formed in volcanic and sedimentary environments through the deposition of silica-rich groundwater. Often found as nodules or filling cavities in volcanic rocks.

Uses & applications

Commonly used in jewelry, as cabochons, beads, and for lapidary carving. Historically used for signet rings and seals.

Geological facts

Carnelian was highly prized in ancient civilizations like Rome and Egypt, where it was believed to provide courage and protection for the soul in the afterlife.

Field identification & locations

Identify by its waxy luster, translucency, and warm reddish-brown color. Common in dry riverbeds or ancient volcanic basalt flows. Found globally in Brazil, India, and Madagascar.