
sedimentary
Banded Agate
Cryptocrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness: 6.5-7.0 (Mohs scale), Color: White with reddish-brown banding, Luster: Waxy to vitreous, Structure: Trigonal (microcrystalline), Specific Gravity: 2.58-2.64
- Hardness
- 6
Identified More sedimentary →
Explore Banded Agate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7.0 (Mohs scale), Color: White with reddish-brown banding, Luster: Waxy to vitreous, Structure: Trigonal (microcrystalline), Specific Gravity: 2.58-2.64
Formation & geological history
Formed in cavities within volcanic or sedimentary rocks where silica-rich groundwater deposited layers of microcrystalline quartz over thousands of years. The banding results from periodic changes in the solution chemistry.
Uses & applications
Commonly used for lapidary work, including jewelry such as beads and cabochons, as well as garden decoration, tumbling, and as emotional healing stones in alternative practices.
Geological facts
Agates are often found as nodules within volcanic rocks but can also be found as secondary deposits in riverbeds and on beaches. The word agate comes from the Achates River in Sicily, where they were first discovered.
Field identification & locations
Identified by its translucency (light can pass through edges) and the presence of fine-grained concentric or planar banding. Harder than steel; it will not be scratched by a knife blade.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary