mineral

Carnelian Agate

Silicon Dioxide (SiO₂)

Hardness: 6.5-7 on Mohs scale. Color: Orange, reddish-brown, brownish-red. Luster: Vitreous to waxy. Crystal Structure: Hexagonal (cryptocrystalline). Cleavage: None. Specific Gravity: 2.58–2.64.

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

Identified April 7, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale. Color: Orange, reddish-brown, brownish-red. Luster: Vitreous to waxy. Crystal Structure: Hexagonal (cryptocrystalline). Cleavage: None. Specific Gravity: 2.58–2.64.

Formation & geological history

Formed through the deposition of silica from groundwater in the cavities of igneous rocks. The reddish color is due to impurities of iron oxide (hematite). Occurs primarily in volcanic rocks like basalt or rhyolite.

Uses & applications

Used extensively in jewelry as beads and cabochons, for lapidary carvings like the obelisk shown, as ornamental stones, and in metaphysical collecting.

Geological facts

Carnelian has been used for over 4,500 years; ancient Egyptians referred to it as the 'setting sun' and used it in amulets. It was also used for signet rings because hot wax does not stick to it.

Field identification & locations

Identify in the field by its translucent properties when held to light and its waxy luster. Common locations include Brazil, India, Uruguay, Madagascar, and the United States (western states).