mineral

Carnelian

Carnelian (Silica, SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Red-orange to brownish-red; Luster: Vitreous to waxy; Crystal structure: Trigonal (cryptocrystalline); Cleavage: None; Specific Gravity: 2.59-2.61.

Hardness: 6
Color: Red-orange to brownish-red
Luster: Vitreous to waxy

Identified June 28, 2026More mineral →

Explore Carnelian in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Red-orange to brownish-red; Luster: Vitreous to waxy; Crystal structure: Trigonal (cryptocrystalline); Cleavage: None; Specific Gravity: 2.59-2.61.

Formation & geological history

Forms primarily in volcanic and sedimentary environments through the deposition of silica from groundwater into cavities (vugs) in volcanic rock. The reddish color is due to iron oxide impurities.

Uses & applications

Widely used since antiquity for jewelry, seal stones, beads, and cabochons. It is also a popular stone for tumbling and crystal collecting.

Geological facts

Ancient Egyptians called carnelian "the setting sun" and believed it helped protect the dead on their journey through the afterlife. It was also famously used in Roman signet rings.

Field identification & locations

Identify in the field by its translucent orange-red color and waxy luster. Commonly found in Brazil, India, Uruguay, Madagascar, and the United States (Oregon and Washington).