mineral

Carnelian

Carnelian Chalcedony (SiO2)

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

Hardness: 6
Color: Orange, reddish-brown to translucent red
Luster: Vitreous to waxy

Identified March 14, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the deposition of silica from groundwater into the cavities of igneous rocks such as basalt or rhyolite. Its reddish hue comes from trace amounts of iron oxide (hematite). Found in varied geological ages spanning millions of years.

Uses & applications

Primarily used in jewelry, lapidary arts (cabochons and beads), and ornamental carvings. Historically significant for making cylinder seals and signet rings.

Geological facts

In antiquity, Carnelian was believed to protect the wearer from bad luck and promote courage. It was one of the twelve stones in the Breastplate of Aaron and widely used by ancient Egyptians for decorative amulets.

Field identification & locations

Identify by its waxy luster, translucency, and warm orange/red hues. It often lacks the banding found in agates. Commonly found in Brazil, India, Uruguay, Madagascar, and parts of the United States (Washington and Oregon).