sedimentary
Agate
Silicon dioxide (chalcedony), SiO2
AI-generated identification · may be incorrectHardness of 6.5-7 on Mohs scale, variable multicolored banding, waxy to vitreous luster, cryptocrystalline structure, conchoidal fracture.
Identified More sedimentary →
Explore Agate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 6.5-7 on Mohs scale, variable multicolored banding, waxy to vitreous luster, cryptocrystalline structure, conchoidal fracture.
Formation & geological history
Forms by the deposition of silica from groundwater in cavities of igneous and sedimentary rocks over millions of years.
Uses & applications
Widely used in ornamental carvings, jewelry, decorative slabs, and precision instruments like mortars and pestles.
Geological facts
Agate bands represent successive layers of microscopic quartz crystals settling out of fluids entering cavity spaces.
Field identification & locations
Identified by its distinctive concentric color banding and waxy luster; commonly found worldwide in volcanic rock cavities.
More like this
Other sedimentary specimens
Fossil-bearing concretion, possibly containing a fossil shell or other organic inclusion
Calcareous concretion; exact fossil and host-rock composition are not identifiable from the image
fossil
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary