mineral

Carnelian Agate

Silicon dioxide (Chalcedony), SiO2

Hardness: 7 on Mohs scale. Color: Brownish-red to orange-red. Luster: Vitreous to waxy. Crystal structure: Trigonal (microcrystalline quartz). Cleavage: None. Specific gravity: 2.58 - 2.64

Hardness: 7 on Mohs scale
Color: Brownish-red to orange-red
Luster: Vitreous to waxy

Identified August 5, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale. Color: Brownish-red to orange-red. Luster: Vitreous to waxy. Crystal structure: Trigonal (microcrystalline quartz). Cleavage: None. Specific gravity: 2.58 - 2.64

Formation & geological history

Forms in the cavities of volcanic rocks and metamorphic rocks through the deposition of silica from groundwater solutions over millions of years.

Uses & applications

Used primarily in jewelry making, as carved gemstones, signet rings, and lapidary art.

Geological facts

Carnelian has been prized since ancient times, frequently used by the ancient Egyptians and Romans for amulets, signet rings, and intaglio seals due to hot wax not sticking to its smooth surface.

Field identification & locations

Identified by its waxy luster, orange-to-red coloration, and conchoidal fracture. Commonly found in river gravels, beaches, and volcanic regions worldwide including Brazil, India, and the USA.