mineral

Carnelian Agate / Chalcedony

Silicon Dioxide (SiO2) - Microcrystalline Quartz

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Orange-brown, translucent to semi-translucent; Luster: Waxy to vitreous; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.64

Hardness: 6
Color: Orange-brown, translucent to semi-translucent
Luster: Waxy to vitreous

Identified July 24, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Orange-brown, translucent to semi-translucent; Luster: Waxy to vitreous; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.64

Formation & geological history

Formed by the precipitation of silica-rich fluids in cavities within volcanic or sedimentary rocks, often developing botryoidal textures and faint color zoning as iron impurities leach in.

Uses & applications

Widely used for lapidary arts, jewelry (cabochons, beads), decorative carvings, and mineral collections.

Geological facts

Carnelian has been used in jewelry making for over 4,500 years, notably in ancient Egyptian, Roman, and Sumerian cultures for seals and amulets.

Field identification & locations

Identified by its waxy luster, smooth conchoidal fracture surfaces, botryoidal growth patterns, and translucent orange-brown color. Commonly found in basaltic decay zones, gravels, and riverbeds in Brazil, India, Madagascar, and parts of Africa.