mineral

Carnelian (Orange Agate/Chalcedony)

Silicon Dioxide (SiO2) - variety of Chalcedony

Hardness: 6.5-7 on Mohs scale; Color: Orange to reddish-brown; Luster: Waxy to vitreous; Crystal Structure: Hexagonal (trigonal) microcrystalline; Cleavage: None; Specific Gravity: 2.58-2.64

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

Identified April 22, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Orange to reddish-brown; Luster: Waxy to vitreous; Crystal Structure: Hexagonal (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, particularly volcanic lavas. The orange color comes from iron oxide (hematite) impurities.

Uses & applications

Used primarily as a semi-precious gemstone in jewelry (beads, cabochons), carved seals, and as decorative pocket stones for collectors.

Geological facts

Carnelian was widely used in ancient Rome for signet rings and seals because hot wax does not stick to it. It has been used for jewelry since the Neolithic period.

Field identification & locations

Identify in the field by its waxy luster, conchoidal (shell-like) fracture, and translucent orange hue. Often found in riverbeds or on beaches in volcanic regions.

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Arenite (SiO2 based)

sedimentary

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Metamorphic

Epidote

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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