gemstone

Red-orange carnelian

Carnelian, a translucent chalcedony variety of quartz (SiO₂)

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; orange-red to brown-red color, commonly waxy to vitreous luster, cryptocrystalline quartz structure, and no visible cleavage. The specimen appears naturally rough or lightly shaped, with translucent edges and iron-oxide coloration.

Identified September 6, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, with iron impurities producing the red-orange color; it is commonly associated with volcanic rocks and ancient sedimentary gravels. Deposits range from Precambrian to recent, rather than representing one specific age.

Uses & applications

Used for beads, cabochons, carvings, seals, and ornamental objects; attractive polished pieces have modest jewelry value.

Geological facts

Carnelian is technically chalcedony, not a separate mineral species. Heating can intensify its red color by converting hydrated iron oxides to hematite-like pigments.

Field identification & locations

Identify it by its orange-red translucency, waxy luster, conchoidal fracture, and hardness sufficient to scratch glass; it should not show strong cleavage. Common sources include India, Brazil, Uruguay, Madagascar, Germany, and the western United States.