mineral

Banded Agate (Gray/Brown)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 (Mohs); Color: Gray, brown, and white banding; Luster: Waxy to vitreous; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific gravity: 2.58-2.64

Hardness: 6
Color: Gray, brown, and white banding
Luster: Waxy to vitreous

Identified June 3, 2026More mineral →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6.5-7 (Mohs); Color: Gray, brown, and white banding; Luster: Waxy to vitreous; Crystal structure: Trigonal/Microcrystalline; Cleavage: None; Specific gravity: 2.58-2.64

Formation & geological history

Forms primarily in volcanic and metamorphic rocks through the deposition of silica from groundwater in rock cavities (geodes) over thousands of years.

Uses & applications

Commonly used in jewelry (cabochons, beads), decorative carvings, and as a collector's stone. Historically used for making precision tools 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 discovered in ancient times.

Field identification & locations

Identify by its waxy luster, translucency when held to light, and characteristic concentric or parallel banding. Commonly found in riverbeds or volcanic regions like Brazil, India, and the USA.