gemstone

Tumbled red-orange stone, likely carnelian

Carnelian, a translucent variety of chalcedony (microcrystalline quartz, SiO₂)

AI-generated identification · may be incorrect

Reddish-orange to brown, waxy to vitreous luster, typically Mohs 6.5–7; quartz’s trigonal crystal system is microscopic, with no visible cleavage. The photo shows a smooth, rounded piece, but does not allow definitive identification.

Identified September 27, 2026More gemstone →

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Physical properties

Formation & geological history

Forms as silica-rich chalcedony filling cavities and fractures, commonly in volcanic rocks; iron oxides produce its warm colors. Such deposits occur in rocks of many geological ages.

Uses & applications

Used for beads, cabochons, ornaments, and small carvings; this piece appears suitable as a modest decorative or lapidary specimen.

Geological facts

Carnelian has been valued since antiquity and was used for seals and jewelry. Similar-looking iron-stained quartz and other chalcedony varieties can be difficult to distinguish visually.

Field identification & locations

Check for translucency at thin edges, a smooth waxy surface, and hardness sufficient to scratch glass; avoid destructive tests on a polished piece. Carnelian is found worldwide, including India, Brazil, Uruguay, and Madagascar.