Carnelian

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Orange, reddish-brown, brownish-red; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal (Microcrystalline); Cleavage: None; Specific gravity: 2.58–2.64

Formation & Geological History

Formed as a cryptocrystalline variety of silica in volcanic and sedimentary environments, often occurring as fillings in cavities (geodes) or as nodules. The red color is caused by impurities of iron oxide (hematite).

Uses & Applications

Predominantly used as a gemstone for jewelry (cabochons, beads), decorative carvings, wax seals, and in metaphysical practices.

Geological Facts

In ancient Rome, carnelian was used for signet rings to seal correspondence as hot wax does not stick to it. It was also highly prized in ancient Egypt to signify social status and was believe to have protective properties.

Field Identification & Locations

Identify by its translucent reddish-orange color and waxy luster. It can be found globally with major deposits in Brazil, India, Madagascar, and Uruguay. Field collectors should look for smooth, translucent nodules in gravel beds or volcanic regions.

Identified on: 5/13/2026

Mode: Standard