mineral

Carnelian

Silicon Dioxide (Quartz variety), SiO2

Hardness of 7 on the Mohs scale, orange to brownish-red color, vitreous to waxy luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65

Identified August 5, 2026More mineral →

Explore Carnelian in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness of 7 on the Mohs scale, orange to brownish-red color, vitreous to waxy luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65

Formation & geological history

Forms in low-temperature environments such as groundwater cavities in volcanic or sedimentary rocks, where silica-rich solutions deposit microscopic quartz crystals colored by iron oxide impurities.

Uses & applications

Used primarily in jewelry, as carved gemstones, beads, and for ornamental displays or crystal healing.

Geological facts

Carnelian has been prized since ancient times, widely used in ancient Rome for signet rings because hot wax does not stick to it, and featured prominently in the jewelry of ancient Egyptian pharaohs.

Field identification & locations

Identified by its characteristic translucent orange-to-red hue and waxy luster, commonly found in Brazil, India, Siberia, and parts of the United States.