gemstone

Tumbled carnelian (probable)

Chalcedony, microcrystalline quartz (SiO₂), iron-oxide colored

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent reddish-brown to orange, waxy/glassy luster, cryptocrystalline structure, no visible cleavage, and conchoidal fracture. The smooth rounded shape indicates tumbling or polishing.

Identified August 27, 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-brown color; deposits range from Cenozoic to much older. Common sources include India, Brazil, Uruguay, Madagascar, and the United States.

Uses & applications

Used for beads, cabochons, carvings, ornamental objects, and inexpensive jewelry; historically used for seals and amulets.

Geological facts

Carnelian is an orange-red variety of chalcedony, closely related to sard; heating can intensify its color. The photograph alone cannot exclude brown jasper or dyed agate.

Field identification & locations

Field identification: test hardness against steel or glass, inspect for translucency and subtle color banding, and check that it does not scratch with a steel knife. A specific identification requires close inspection or testing.