mineral

Carnelian

Carnelian (Chalcedony / SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Orangish-red to brownish-red due to iron impurities; Luster: Waxy to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.64

Hardness: 6
Color: Orangish-red to brownish-red due to iron impurities
Luster: Waxy to vitreous

Identified May 15, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed in volcanic and sedimentary environments when silica-rich fluids permeate cavities in host rock. Its distinctive color is primarily caused by iron oxide (hematite) inclusions.

Uses & applications

Widely used for lapidary work, jewelry (beads, cabochons), carvings, and seals. Primarily valued by collectors and crystal healing enthusiasts.

Geological facts

Carnelian was used by the Romans to make signet rings because hot wax does not stick to it. It has been a significant gemstone since the Neolithic period.

Field identification & locations

Identifiable by its translucent to semi-opaque orange-red hue and waxy luster. Commonly found in Brazil, India, Uruguay, and Madagascar. In the field, look for conchoidal fractures and a smooth, waxy surface.