mineral

Tumbled carnelian/chalcedony

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

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; translucent orange to reddish-brown with a waxy/glassy luster and no visible cleavage. Its rounded, polished form indicates tumbling; color commonly comes from iron oxides or hydroxides.

Identified August 16, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities and fractures in volcanic rocks, with iron producing the warm coloration. Chalcedony deposits range from ancient to geologically recent and occur worldwide.

Uses & applications

Used for cabochons, beads, carvings, ornaments, and inexpensive jewelry; polished pieces are popular among mineral collectors.

Geological facts

Carnelian is traditionally associated with vitality and has been used in seals and jewelry since antiquity, including ancient Egypt and Rome.

Field identification & locations

Identify it by its orange-red color, smooth waxy surface, translucence, and lack of cleavage; a steel file should not easily scratch it. Common sources include India, Brazil, Uruguay, Madagascar, and the United States.