gemstone

Tumbled orange-brown stone, likely carnelian

Carnelian, a chalcedony variety of microcrystalline quartz (SiO₂), possibly iron-stained quartzite or jasper

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; orange to honey-brown color, translucent to opaque, and typically waxy to vitreous luster. It has cryptocrystalline structure, no visible cleavage, and conchoidal fracture; exact identification requires testing.

Identified August 16, 2026More gemstone →

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Physical properties

Formation & geological history

Carnelian forms when iron-bearing silica fills cavities and fractures in volcanic rocks, commonly during low-temperature groundwater deposition. Its geological age varies widely, from relatively young deposits to Paleozoic and older host rocks.

Uses & applications

Used for beads, cabochons, carvings, ornamental objects, and inexpensive jewelry; tumbled pieces are mainly collectible or decorative.

Geological facts

The orange color results from iron oxides or hydroxides. Heating can intensify its red-orange color, and some commercial “carnelian” is dyed agate.

Field identification & locations

Common sources include India, Brazil, Uruguay, Madagascar, and Germany. Check for uniform dye concentration, translucency at thin edges, glassy conchoidal fracture, and scratch resistance; a gemological test is needed to distinguish it from jasper or quartzite.