Rock Identifier
Carnelian (a variety of Chalcedony) (Silicon Dioxide (SiO2) with Iron Oxide impurities) — mineral
mineral

Carnelian (a variety of Chalcedony)

Silicon Dioxide (SiO2) with Iron Oxide impurities

Hardness: 6.5-7 on Mohs scale; Color: Reddish-orange to brownish-red; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.64

Hardness
6
Color
Reddish-orange to brownish-red
Luster
Vitreous to waxy
Identified More mineral

Identify your own rocks.

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

Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Reddish-orange to brownish-red; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.64

Formation & geological history

Formed through the deposition of silica from groundwater in the cavities of igneous rocks. The reddish color is caused by impurities of iron oxide (hematite). It is often found in volcanic environments.

Uses & applications

Predominantly used as a gemstone for jewelry (beads, cabochons, set rings) and ornamental carvings/figurines. Historically used for cylinder seals and signet rings.

Geological facts

In ancient times, carnelian was believed to give courage in battle and protect against poverty. The prophet Muhammad is said to have worn a carnelian signet ring set in silver.

Field identification & locations

Identify by its waxy luster, translucency, and warm orange-red palette. In the field, look for nodules with a smooth, weathered exterior that reveal a colorful interior when broken. Commonly found in Brazil, India, Madagascar, and Uruguay.