Carnelian

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Translucent reddish-brown to orange; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (Trigonal), cryptocrystalline; Cleavage: None; Specific Gravity: 2.58-2.64

Formation & Geological History

Formed as a cryptocrystalline variety of silica in volcanic and sedimentary rocks. It gets its color from iron oxide impurities. It is often found in geodes or as river pebbles.

Uses & Applications

Predominantly used as a gemstone in jewelry (cabochons, beads), decorative carvings, and seal stones. Historically used for signet rings.

Geological Facts

Ancient Egyptians called carnelian 'the setting sun' and believed it had protective properties. It was one of the first stones used in bead-making in the Neolithic period.

Field Identification & Locations

Identify in the field by its waxy luster, conchoidal fracture, and lack of visible crystal structure (unlike macrocrystalline quartz). Commonly found in Brazil, India, Madagascar, and Uruguay.

Identified on: 4/26/2026

Mode: Standard