mineral

Carnelian / Chalcedony

Cryptocrystalline Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs); Color: Orange, reddish-brown, honey-yellow; Luster: Waxy to vitreous; Structure: Trigonal (microcrystalline); Cleavage: None; Fracture: Conchoidal; Translucent to semi-opaque.

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

Identified July 5, 2026More mineral →

Explore Carnelian / Chalcedony in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6.5-7 (Mohs); Color: Orange, reddish-brown, honey-yellow; Luster: Waxy to vitreous; Structure: Trigonal (microcrystalline); Cleavage: None; Fracture: Conchoidal; Translucent to semi-opaque.

Formation & geological history

Formed by the deposition of silica-rich groundwater in cavities of igneous and sedimentary rocks. The orange coloration is caused by iron oxide (limonite or hematite) impurities. Often found as water-worn pebbles in river beds.

Uses & applications

Extensively used in lapidary work, jewelry (beads, cabochons, carved seals), and as a collector's mineral. Industrially used for its hardness in abrasive applications.

Geological facts

Carnelian was prized by ancient Romans and Greeks for signet rings because hot wax does not stick to it. It has been used for beads since the Neolithic period over 5,000 years ago.

Field identification & locations

Identified by its waxy luster, translucency, and inability to be scratched by a steel knife. Frequently found in river gravel or beach wash, particularly in basaltic regions.