mineral

Carnelian (Chalcedony)

Silicon Dioxide (SiO2) with trace Iron Oxide

Hardness: 6.5-7.0 (Mohs); Color: Orange to reddish-brown; Luster: Waxy to vitreous; Crystal Structure: Trigonal (Microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.64

Hardness: 6
Color: Orange to reddish-brown
Luster: Waxy to vitreous

Identified April 18, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6.5-7.0 (Mohs); Color: Orange to reddish-brown; Luster: Waxy to vitreous; Crystal Structure: Trigonal (Microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.64

Formation & geological history

Formed through the deposition of silica from groundwater into cavities of volcanic rocks (basalt/rhyolite) or sedimentary formations. Its red/orange tint is caused by iron impurities that oxidize during formation.

Uses & applications

Predominantly used as a gemstone in jewelry, for lapidary work (beads, cabochons), and in metaphysical or spiritual practices. Historically used for signet rings and seals.

Geological facts

Ancient Egyptians called carnelian "the setting sun" and believed it possessed powers to revitalize the soul. It is one of the oldest gemstones used by humans, with evidence of its use dating back to the Neolithic period.

Field identification & locations

Identify by its characteristic waxy luster and translucent orange hue. Look for it in riverbeds or volcanic regions. Collectors often seek pieces with deep, uniform red-orange saturation without distracting inclusions.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

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