mineral

Carnelian

Carnelian (Silica, SiO2)

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 May 9, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

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 by the precipitation of silica from groundwater in the cavities of igneous rocks, particularly volcanic rocks like basalt. The red color is derived from iron oxide impurities. Specimens can range from thousands to millions of years old.

Uses & applications

Primarily used in jewelry (cabochons, beads), decorative carvings, and as a popular semi-precious gemstone for collectors.

Geological facts

In ancient Egypt, carnelian was known as 'the setting sun' and was used in the burial of the dead to assist in the afterlife journey. It is one of the oldest gemstones used for seals and amulets.

Field identification & locations

Identify in the field by its distinctive waxy luster and translucency when held to light. It lacks the internal banding of agate. Commonly found in Brazil, India, Madagascar, and Uruguay.