mineral

Tumbled carnelian and related stones

Carnelian: orange-red chalcedony, microcrystalline SiO₂; the dark central piece may be hematite- or jasper-rich material

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; translucent red, orange, or brown color, waxy to vitreous luster, cryptocrystalline quartz, and no visible cleavage. These pieces are rounded and polished, likely commercially tumbled.

Identified August 26, 2026More mineral →

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Physical properties

Formation & geological history

Chalcedony forms when silica-rich groundwater fills cavities and fractures in volcanic rocks, commonly during the Cenozoic or older. Iron impurities produce carnelian’s red-orange color; associated jasper or ironstone forms through silica replacement and oxidation.

Uses & applications

Used for beads, cabochons, carvings, and inexpensive jewelry; jasper and ironstone are also ornamental materials. Tumbled specimens are primarily sold for collecting and décor.

Geological facts

Carnelian is a variety of chalcedony, not a separate mineral species. Color may be enhanced by heating or dyeing, especially in commercial tumbled stones.

Field identification & locations

Identify carnelian by its orange-red translucent body, smooth waxy surface, and inability to scratch glass only weakly or variably; quartz-rich material scratches steel. Common sources include India, Brazil, Uruguay, Madagascar, and Indonesia.