gemstone

Tumbled reddish-brown stone, likely carnelian

Chalcedony, a microcrystalline variety of quartz (SiO₂)

AI-generated identification · may be incorrect

Smooth, opaque to slightly translucent reddish-brown surface with a vitreous-to-waxy luster; quartz hardness 6.5–7, trigonal crystal structure, no cleavage. The photo alone cannot confirm the identification; similar jasper or other chalcedony is possible.

Identified October 8, 2026More gemstone →

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Physical properties

Formation & geological history

Typically forms as silica-rich chalcedony filling cavities and fractures in volcanic rocks; iron oxides produce red and brown colors. Such deposits occur across many geological ages.

Uses & applications

Used for beads, cabochons, jewelry, and decorative objects; common tumbled pieces are mainly collectible keepsakes.

Geological facts

Carnelian is traditionally valued for its warm color and has been used in engraved seals and jewelry since antiquity.

Field identification & locations

Look for a smooth, hard surface and consistent reddish color; chalcedony commonly occurs in volcanic cavities and alluvial gravels. The stone appears tumbled, so natural texture and diagnostic features are obscured.