gemstone

Polished carnelian

Carnelian, a red-orange variety of chalcedony (microcrystalline quartz, SiO₂)

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; translucent orange-red body with vitreous to waxy luster, commonly colored by iron oxides. It has cryptocrystalline quartz structure and no visible cleavage; conchoidal fracture is typical.

Identified September 8, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater deposits chalcedony in volcanic cavities or fractures, with iron producing the orange-red color; deposits range from ancient to geologically recent. Heat treatment can intensify the red coloration.

Uses & applications

Used for cabochon jewelry, beads, seals, carvings, and ornamental objects. It is durable enough for everyday jewelry but may scratch from harder materials.

Geological facts

Carnelian is a traditional variety of agate/chalcedony and has been used in seals and jewelry since antiquity, including ancient Egypt and Rome.

Field identification & locations

Identify by its orange-red translucency, smooth polish, and lack of cleavage; glass may show bubbles and a more uniform appearance. Common sources include India, Brazil, Uruguay, Madagascar, and Germany.