mineral

Carnelian (a variety of Chalcedony)

SiO2 (Silicon Dioxide) - Cryptocrystalline Quartz

Hardness: 6.5-7 (Mohs scale); Color: Translucent orange to reddish-brown (caused by iron oxide impurities); Luster: Waxy to vitreous; Crystal structure: Trigonal/Hexagonal (microscopic fibers); Cleavage: None; Specific gravity: 2.58–2.64.

Hardness: 6
Luster: Waxy to vitreous

Identified March 7, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica in gas cavities (vesicles) of volcanic rocks or in sedimentary environments. Iron oxide leaches into the silica to provide the orange hue. Found in deposits of many geological ages, often concentrated in riverbeds or beaches through weathering.

Uses & applications

Primarily used as a gemstone in jewelry (beads, cabochons), for intaglios and seals, and in decorative carvings or spiritual practices.

Geological facts

Carnelian was highly prized in ancient Mesopotamia and Egypt, where it was thought to provide protection for the soul. It was used for royal cylinder seals and talismans worn by Pharaohs.

Field identification & locations

Identify by its waxy luster, translucency, and inability to be scratched by a steel knife. It is commonly found in India, Brazil, Uruguay, and the United States (notably the PNW and Lake Superior region). Look for smooth, water-worn orange 'pebbles' along shorelines.

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