sedimentary
Chert
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, earthy to vitreous luster, conchoidal fracture, and colors ranging from brown and gray to white.
Identified More sedimentary →
Explore Chert in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 7 on the Mohs scale, earthy to vitreous luster, conchoidal fracture, and colors ranging from brown and gray to white.
Formation & geological history
Formed through the accumulation of siliceous skeletal remains of marine organisms or the chemical replacement of limestone during sedimentary deposition.
Uses & applications
Historically used for making stone tools and weapons due to its sharp edges when fractured; modern use includes decorative landscaping and abrasives.
Geological facts
Chert forms in nodules within limestone or chalk formations and was a primary material for prehistoric stone knapping worldwide.
Field identification & locations
Identify by its extreme hardness, waxy luster, and sharp conchoidal fracture edges; commonly found in limestone and chalk deposits globally.
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