mineral

Carnelian (Red Chalcedony)

SiO2 (Silicon Dioxide with Iron Oxide impurities)

Hardness: 6.5-7.0 (Mohs scale), Color: Orangey-red to brownish-red, Luster: Vitreous to waxy, Crystal Structure: Trigonal (microcrystalline/cryptocrystalline), Cleavage: None, Specific Gravity: 2.58-2.64

Hardness: 6

Identified April 2, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the deposition of silica from groundwater into cavities of igneous rocks such as basalt or rhyolite. Its color is derived from iron oxide (hematite) impurities.

Uses & applications

Used primarily in jewelry (beads, cabochons), lapidary art, seal stones, and as a popular specimen for crystal collectors.

Geological facts

Carnelian was highly prized in ancient times; ancient Egyptians believed it had protective properties, and it was used in the Hebrew high priest's breastplate and the rings of Islamic tradition.

Field identification & locations

Identify by its translucent nature and reddish-orange hue with a waxy luster. Commonly found in India, Brazil, Madagascar, and Uruguay. Field collectors should look for chalcedony nodules in volcanic host rocks.

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