mineral

Carnelian Agate

Chalcedony (Silicon Dioxide, SiO2)

Hardness: 6.5–7 on Mohs scale; Color: Translucent orange to reddish-brown; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific gravity: 2.58–2.64

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

Identified April 22, 2026More mineral →

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Physical properties

Hardness: 6.5–7 on Mohs scale; Color: Translucent orange to reddish-brown; Luster: Vitreous to waxy; Crystal structure: 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 hue is caused by iron oxide impurities.

Uses & applications

Commonly used in lapidary work for cabochons, beads, and carved jewelry. It has a high historical value for seals and amulets.

Geological facts

In ancient times, carnelian was believed to give courage in battle. It was widely used in ancient Egypt and Rome for signet rings because hot wax does not stick to it.

Field identification & locations

Identify in the field by its waxy texture and translucent orange color when held to light. Look for it in riverbeds or gravel deposits in volcanic regions like Brazil, India, or the Pacific Northwest, USA.