gemstone

Tumbled carnelian (likely chalcedony)

Carnelian, orange-red cryptocrystalline quartz (SiO₂), a variety of chalcedony

AI-generated identification · may be incorrect

Orange to red, translucent at thin edges, waxy/glassy luster, no visible crystals or cleavage; Mohs hardness about 6.5–7, specific gravity ~2.60. The rounded shape and smooth surface indicate tumbling or polishing, though iron staining may produce the color.

Identified August 10, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, with iron oxides creating orange-red coloration; commonly Cenozoic or older depending on its host rock. The specimen may have been collected and subsequently human-processed.

Uses & applications

Used for cabochons, beads, carvings, and inexpensive jewelry; attractive small tumbled pieces commonly sell for about $1–$10, or $10–$30 if unusually vivid, translucent, and well patterned.

Geological facts

Carnelian is not a separate mineral species but a color variety of chalcedony. Heating can intensify its red-orange color, and some commercial material is dyed or heat-treated.

Field identification & locations

Identify by its waxy translucence, hardness, lack of cleavage, and orange-red iron coloration; it should scratch glass but not be scratched easily by a steel knife. Carnelian/chalcedony is plausible around the Sierra Nevada foothills near 38.7°N, 121.3°W, although the exact source cannot be determined from this image.