mineral

Carnelian (Red-Orange Chalcedony)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Translucent red, orange, or reddish-brown; Luster: Vitreous to waxy; Crystal Structure: Trigonal (cryptocrystalline); Cleavage: None; Specific Gravity: 2.58-2.64.

Hardness: 6
Color: Translucent red, orange, or reddish-brown
Luster: Vitreous to waxy

Identified April 11, 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 through the deposition of silica from groundwater within cavities of igneous rocks, particularly lavas. The color is derived from iron oxide impurities. These can range from modern formations to millions of years old.

Uses & applications

Primarily used as a gemstone in jewelry (cabochons, beads), decorative carvings, wax seals, and spiritual/metaphysical collecting.

Geological facts

Carnelian was widely used in ancient Rome and Greece for signet rings because hot wax does not stick to it. It has been found in archaeological sites dating back to the Neolithic era.

Field identification & locations

Identify by its translucent, waxy appearance and warm reddish-orange hue. It lacks the banding of agate. Commonly found in Brazil, India, Uruguay, and Madagascar. In the field, look for pebbles with a smooth, water-worn exterior and a 'glowing' quality when held to the light.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral

Epidote

Epidote - Ca2(Al2,Fe3+)3(SiO4)3(OH)

mineral