gemstone

Tumbled carnelian (likely)

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

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent orange-red body, waxy/glassy luster, cryptocrystalline quartz structure, and no visible cleavage. The smooth rounded form indicates tumbling and polishing; coloration commonly comes from iron oxides.

Identified August 25, 2026More gemstone →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures, later acquiring iron staining during weathering; deposits range from ancient volcanic-hosted veins to younger sedimentary gravels. Exact age cannot be determined visually.

Uses & applications

Used for cabochons, beads, carvings, seals, and ornamental objects; durable but less valuable than transparent fine agate or high-grade gemstones.

Geological facts

Carnelian is historically important in Egyptian, Greek, Roman, and Islamic jewelry and seal-making. Stronger red-orange color and translucency generally increase desirability.

Field identification & locations

Identify by its orange-to-red color, waxy translucency, very fine texture, and ability to scratch ordinary glass; quartz does not react with dilute acid. Common sources include India, Brazil, Uruguay, Madagascar, and Germany.