Mineral

Banded Agate (Jasper-Agate)

Silicon Dioxide (SiO₂)

Hardness: 6.5–7 on the Mohs scale. Color: Brown, red, and white/gray banding. Luster: Vitreous to waxy. Crystal structure: Cryptocrystalline (Trigonal). Cleavage: None (Conchoidal fracture). Specific Gravity: 2.60–2.65.

Hardness: 6
Color: Brown, red, and white/gray banding
Luster: Vitreous to waxy

Identified March 25, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Formed through the deposition of silica from groundwater into the cavities of igneous rocks such as basalt or rhyolite. The banding results from rhythmic crystallization over thousands of years. Often found in volcanic ash beds or sedimentary deposits.

Uses & applications

Primarily used for lapidary arts, jewelry (cabochons), interior decoration, and as architectural accents. Historically used for making hardstone cameos and amulets.

Geological facts

Agate belongs to the chalcedony family. The distinct bands are caused by different mineral impurities (like iron or manganese oxide) entering the solution during formation. It was named by Theophrastus after the Achates River in Sicily.

Field identification & locations

Identify in the field by its distinct waxy luster and translucent to opaque concentric banding. Often found along riverbeds, beaches, or in volcanic terrains. Tips for collectors: Look for high color contrast and lack of fractures; common in areas like Lake Superior (USA), Brazil, and India.