mineral

Agate

Silicon Dioxide (SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Multi-colored with banding; Luster: Waxy to vitreous; Crystal Structure: Cryptocrystalline (Trigonal); Cleavage: None; Specific Gravity: 2.58-2.64

Hardness: 6
Color: Multi-colored with banding
Luster: Waxy to vitreous

Identified July 12, 2026More mineral →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Multi-colored with banding; Luster: Waxy to vitreous; Crystal Structure: Cryptocrystalline (Trigonal); Cleavage: None; Specific Gravity: 2.58-2.64

Formation & geological history

Formed primarily in volcanic and metamorphic rocks. Created through the deposition of silica from groundwater in the cavities of igneous rocks over millions of years.

Uses & applications

Used widely in jewelry, lapidary arts, ornamental carvings, and industrially for precision pendulums and laboratory mortars and pestles due to its hardness.

Geological facts

Agate is a variety of chalcedony. The name comes from the Achates River in Sicily, where agates were first found in ancient times. It has been used as a gemstone for over 3,000 years.

Field identification & locations

Identify by its characteristic color banding and waxy appearance. Often found in riverbeds, lake shores (like Lake Superior), and volcanic regions. Collectors look for unique patterns and translucency.