Carnelian (Red Agate)

Physical Properties

Hardness: 6.5-7 (Mohs scale), Color: Brownish-red to orange, Luster: Vitreous to waxy, Crystal Structure: Hexagonal (microcrystalline), Cleavage: None, Specific Gravity: 2.58-2.64

Formation & Geological History

Formed in volcanic and sedimentary rocks as moisture-rich silica precipitates in cavities. Often found as rounded water-worn pebbles in riverbeds or beaches.

Uses & Applications

Primarily used in jewelry (cabochons, beads), decorative carvings, and as a semi-precious gemstone in metaphysical practices.

Geological Facts

Carnelian was used widely in ancient Rome to make signet rings for imprinting wax seals, as hot wax does not stick to it. It has been used for ornamentation for over 4,500 years, dating back to the Indus Valley Civilization.

Field Identification & Locations

Identify by its translucent brownish-red hue and waxy surface. Look in river gravels or coastal areas known for volcanic activity, such as parts of India, Brazil, or Oregon, USA.

Identified on: 4/18/2026

Mode: Standard