mineral

Tumbled carnelian

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

AI-generated identification · may be incorrect

Mohs hardness 6.5–7; translucent orange-brown color, vitreous to waxy luster, cryptocrystalline structure, no visible cleavage, and specific gravity about 2.6. The pictured polished pebble is consistent with carnelian, though exact identification requires testing.

Identified August 25, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater deposits chalcedony in volcanic cavities and fractures, with iron oxides producing its orange-red color. Deposits range from Precambrian to much younger volcanic settings.

Uses & applications

Used for beads, cabochons, carvings, seals, and ornamental objects; durable enough for jewelry and decorative stone.

Geological facts

Carnelian has been prized since antiquity in Egyptian, Roman, and Mesopotamian jewelry. Heating can intensify its red-orange color.

Field identification & locations

Identify by its orange-red translucent body, smooth waxy appearance, hardness, and lack of cleavage; it commonly occurs with agate in volcanic rocks. Common sources include India, Brazil, Uruguay, Madagascar, and Germany.