Carnelian Agate

Physical Properties

Hardness: 6.5–7 (Mohs scale); Color: Orange, reddish-brown, or deep red; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58–2.64

Formation & Geological History

Formed from the deposition of silica from groundwater in cavities of igneous rocks. The color is derived from iron oxide impurities that have been heated over geological time.

Uses & Applications

Predominantly used in jewelry, beadwork, and cabochons. Historically used for cylinder seals and signet rings because hot wax does not stick to it.

Geological Facts

Ancient Romans and Greeks used carnelian for intaglio rings. It was believed to provide courage in battle and is often associated with the 'Solar Plexus' chakra in metaphysical traditions.

Field Identification & Locations

Identify by its translucent orange/red color and characteristic curved (conchoidal) fracture. In the field, look for pebbles with a waxy exterior in riverbeds or volcanic regions like Brazil, India, or Madagascar.

Identified on: 4/13/2026

Mode: Standard