mineral
Banded Agate (Tumbled Chalcedony)
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 6.5-7 on the Mohs scale. Luster: Waxy to vitreous. Color: Creamy white, tan, grayish-brown with dark brown to black banding. Structure: Microcrystalline quartz (trigonal system). Specific gravity: ~2.6.
- Hardness
- 6
- Luster
- Waxy to vitreous
Identified More mineral →
Explore Banded Agate (Tumbled Chalcedony) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 on the Mohs scale. Luster: Waxy to vitreous. Color: Creamy white, tan, grayish-brown with dark brown to black banding. Structure: Microcrystalline quartz (trigonal system). Specific gravity: ~2.6.
Formation & geological history
Formed in cavities within volcanic or metamorphic rocks when silica-rich hydrothermal fluids precipitate layers of microcrystalline quartz over long geological periods.
Uses & applications
Popular for lapidary arts, wire-wrapping, jewelry making, polished stone collections, and ornamental crafts.
Geological facts
Agate is named after the Achates River (now the Dirillo River) in Sicily, where it was discovered by ancient Greeks. Each banded specimen is unique due to varying trace mineral inclusions during formation.
Field identification & locations
Identified by its smooth, polished texture, translucent to opaque body, and characteristic layered banding patterns. Commonly found along riverbeds, beaches, and weathered volcanic rock deposits worldwide, including the US, Brazil, and Madagascar.
More like this
Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Septarian Pebble
Septarian nodule / Concretion
sedimentary