Carnelian (Carnelian Agate)

Physical Properties

Hardness: 6.5-7 on Mohs scale; Color: Reddish-orange to brownish-red; Luster: Vitreous to waxy; Crystal Structure: Trigonal (cryptocrystalline); Cleavage: None; Specific Gravity: 2.58-2.64.

Formation & Geological History

Formed as a cryptocrystalline variety of silica in igneous and sedimentary environments, often occurring in volcanic cavities (vugs) or as nodules. The reddish color is derived from iron oxide impurities.

Uses & Applications

Predominantly used as a gemstone in jewelry (cabochons, beads), decorative carvings, wax seals, and as a popular specimen for crystal collecting.

Geological Facts

In antiquity, carnelian was believed to protect the wearer from bad luck and anger. It was used by ancient Egyptians for amulets and by Romans for signet rings because hot wax does not stick to it.

Field Identification & Locations

Identify by its translucent reddish-orange hue and waxy surface. Look for it in areas with high volcanic activity or in riverbeds as water-worn pebbles. It is frequently tumbled to bring out its luster.

Identified on: 4/26/2026

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