mineral

Carnelian / Chalcedony

Silicon Dioxide (SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Reddish-orange, honey-yellow, amber to light brown; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline quartz); Cleavage: None, conchoidal fracture; Specific Gravity: 2.58-2.64

Hardness: 6
Color: Reddish-orange, honey-yellow, amber to light brown
Luster: Vitreous to waxy

Identified July 23, 2026More mineral →

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Physical properties

Formation & geological history

Forms at low temperatures through the deposition of silica from water solutions into cavities and veins in volcanic or sedimentary rocks. Commonly associated with basaltic lava flows.

Uses & applications

Popular as a lapidary material, used in gemstone jewelry, beads, polished cabochons, carvings, and decorative collectibles.

Geological facts

Carnelian's orange-red coloration comes from iron oxide (hematite) impurities. It has been used for over 4,500 years, being revered in ancient Egypt, Rome, and Sumer as a talisman for courage and protection.

Field identification & locations

Identified by its waxy-to-glassy luster, translucent honey to orange color, and shell-like (conchoidal) fracture pattern. Commonly found along stream beds, gravel bars, and volcanic terrains in regions such as Brazil, India, Madagascar, and the Pacific Northwest, USA.