sedimentary
Agate
Silicon Dioxide (Chalcedony), SiO2
AI-generated identification · may be incorrectHardness of 6.5 to 7 on the Mohs scale, waxy luster, and conchoidal fracture. Displays banded patterns of various colors formed by alternating layers of microcrystalline quartz.
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 to 7 on the Mohs scale, waxy luster, and conchoidal fracture. Displays banded patterns of various colors formed by alternating layers of microcrystalline quartz.
Formation & geological history
Forms primarily within cavities of volcanic and metamorphic rocks through the deposition of silica-rich groundwater over millions of years.
Uses & applications
Widely used in ornamental jewelry, decorative carvings, lapidary art, and precision instrument bearings.
Geological facts
Ancient civilizations valued agates for talismans and healing amulets, believing they could ward off storms and bring favor.
Field identification & locations
Easily identified by its distinctive concentric banding and waxy texture, commonly found in riverbeds and volcanic regions worldwide.
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