mineral

Polished carnelian

Carnelian, orange-red chalcedony (microcrystalline quartz, SiO₂)

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent orange to reddish-brown color, waxy to vitreous luster, cryptocrystalline quartz structure, and no visible cleavage. The rounded, glossy form indicates a tumbled or polished specimen; internal grayish areas may be inclusions or surface reflections.

Identified September 17, 2026More mineral →

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Physical properties

Formation & geological history

Forms when iron impurities color chalcedony in silica-rich volcanic cavities, veins, or sedimentary replacements; deposits range from ancient to recent geological ages. Common sources include India, Brazil, Uruguay, Madagascar, and Germany.

Uses & applications

Used for beads, cabochons, carvings, seals, and inexpensive jewelry; also collected as a decorative gemstone. It is not generally used as a construction stone.

Geological facts

Carnelian is a variety of chalcedony closely related to sard; stronger red-orange color usually reflects higher iron content. Ancient Egyptians and Romans used it for amulets, signet rings, and engraved gems.

Field identification & locations

Identify it by its orange-red color, translucency, waxy luster, lack of cleavage, and ability to scratch glass; dyeing and heat treatment are common. The pictured piece could also be orange dyed agate, which requires testing or magnification to distinguish confidently.