mineral

Tumbled orange chalcedony (likely carnelian)

Cryptocrystalline quartz, SiO₂; orange variety commonly called carnelian

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent honey-orange color, waxy to vitreous luster, and no visible crystal faces or cleavage. The rounded shape indicates mechanical tumbling and polishing; color may reflect iron impurities or enhancement.

Identified August 31, 2026More mineral →

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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 relatively young to Cenozoic and older. It is commonly associated with basaltic cavities and weathered silica deposits.

Uses & applications

Used for cabochons, beads, carvings, and inexpensive jewelry; tumbled pieces are popular decorative and collecting specimens.

Geological facts

Carnelian is a variety of chalcedony, itself a microcrystalline form of quartz. Stronger red-orange color and translucency generally increase desirability.

Field identification & locations

Identify it by its uniform waxy appearance, hardness, translucency, and lack of cleavage; it should scratch glass but not be scratched by a steel knife. Common sources include India, Brazil, Uruguay, Madagascar, and the United States.