mineral

Tumbled carnelian/chalcedony

Carnelian, a translucent variety of microcrystalline quartz (SiO₂)

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; orange, honey-brown, and reddish coloration with waxy to vitreous luster. It has cryptocrystalline structure, no visible cleavage, conchoidal fracture, and typically moderate specific gravity (~2.60).

Identified September 3, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, with iron oxides producing the orange-red color; commonly associated with volcanic rocks and Cenozoic–older sedimentary deposits.

Uses & applications

Used for beads, cabochons, carvings, and decorative tumbled stones; historically valued as an ornamental gemstone and seal material.

Geological facts

Carnelian’s color ranges from pale orange to deep red-brown; heating can intensify or alter the coloration. Similar-looking orange chalcedony may be sold under the broader name “carnelian.”

Field identification & locations

Common in India, Brazil, Uruguay, Madagascar, Germany, and the United States. Identify it by translucency, waxy surface, conchoidal fracture, and resistance to scratching by a steel blade; this specimen is visibly tumbled and polished.