mineral

Raw carnelian/chalcedony

Microcrystalline quartz (SiO₂), orange chalcedony with iron-oxide coloration

AI-generated identification · may be incorrect

Hardness 6.5–7 Mohs; translucent white, orange, and reddish-brown zones; waxy to vitreous luster; cryptocrystalline quartz with no visible cleavage and conchoidal fracture. Specific gravity is approximately 2.60–2.65.

Identified September 11, 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 oxides producing orange-red colors; specimens may develop over millions of years, commonly in Cenozoic to older volcanic terrains.

Uses & applications

Used for cabochons, beads, carvings, and ornamental objects; attractive rough pieces are collected, while high-quality evenly colored carnelian is used in jewelry.

Geological facts

Carnelian is an orange-red variety of chalcedony; darker brown areas commonly reflect concentrated iron oxides or included host material.

Field identification & locations

Identify by its waxy translucency, curved fracture, lack of cleavage, and hardness sufficient to scratch ordinary glass. Common sources include India, Brazil, Uruguay, Madagascar, and the western United States.