mineral

Banded Agate

Silicon Dioxide (SiO2)

Hardness: 6.5-7 on Mohs scale; Color: Gray, white, and translucent bands; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture).

Hardness: 6
Color: Gray, white, and translucent bands
Luster: Vitreous to waxy

Identified May 9, 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 on Mohs scale; Color: Gray, white, and translucent bands; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture).

Formation & geological history

Formed in cavities of volcanic rocks (basalt or rhyolite) where silica-rich groundwater deposits layers of chalcedony over time. Frequently found in regions with ancient volcanic activity.

Uses & applications

Used extensively in jewelry (cabochons, beads), decorative carvings, and industrially for burnishing tools or precision bearings due to its hardness.

Geological facts

Agate is a variety of chalcedony. The banding is caused by the rhythmic crystallization of silica. It has been used in jewelry for over 3,000 years, dating back to ancient Greece and Egypt.

Field identification & locations

Identify in the field by its distinct colorful banding, waxy texture when wet, and superior hardness compared to common stones. Common in riverbeds and glacial deposits.