gemstone

Tumbled orange chalcedony (likely carnelian)

Chalcedony, microcrystalline quartz (SiO₂), commonly colored by iron oxides

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent orange to honey-brown, waxy to vitreous luster, cryptocrystalline structure, no visible cleavage, and specific gravity about 2.6. The rounded, polished surface and pale internal fractures are consistent with tumbled chalcedony.

Identified August 28, 2026More gemstone →

Explore Tumbled orange chalcedony (likely carnelian) in the encyclopedia →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures in volcanic rocks, with iron producing orange-red coloration; deposits range from ancient to relatively young. Common sources include Brazil, India, Uruguay, Madagascar, and the western United States.

Uses & applications

Used for beads, cabochons, carvings, ornaments, and lapidary pieces; historically used for seals and amulets. Ordinary tumbled pieces have modest commercial value.

Geological facts

Carnelian is the orange-red variety of chalcedony, while paler orange material may be sold simply as orange chalcedony. Color can be enhanced by heating or dyeing.

Field identification & locations

Identify it by its uniform waxy appearance, high hardness, lack of cleavage, translucency at edges, and resistance to scratching by steel; glassy-looking imitation glass is less diagnostic. The surrounding countertop appears to be granite, not part of the specimen.