mineral

Tumbled carnelian

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

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; translucent reddish-brown with a vitreous to waxy luster and no visible cleavage. Its quartz crystals are microscopic, so the structure appears smooth and uniform.

Identified September 25, 2026More mineral →

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Physical properties

Mohs hardness 6.5–7; translucent reddish-brown with a vitreous to waxy luster and no visible cleavage. Its quartz crystals are microscopic, so the structure appears smooth and uniform.

Formation & geological history

Forms as silica-rich chalcedony, commonly filling cavities and veins in volcanic rocks; iron oxides impart the color. It occurs in rocks of many ages, rather than having one specific geological age.

Uses & applications

Used for beads, jewelry, carvings, and ornamental objects; historically valued for seals and amulets.

Geological facts

Carnelian is commonly heat-treated or dyed to intensify its color; natural color may show subtle variation or banding.

Field identification & locations

Look for a hard, smooth, translucent orange-red stone that can scratch glass and lacks cleavage; common sources include India, Brazil, and Uruguay. This specimen is polished and its exact identity cannot be confirmed from appearance alone.