sedimentary
Chert
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy luster, conchoidal fracture, and colors ranging from white to gray, brown, or black.
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, waxy luster, conchoidal fracture, and colors ranging from white to gray, brown, or black.
Formation & geological history
Formed through the chemical precipitation of silica from aqueous solutions or the accumulation of siliceous skeletal remains in marine environments.
Uses & applications
Historically used for making stone tools and weapons due to its sharp conchoidal fracture; occasionally used for decorative landscaping.
Geological facts
Ancient humans heavily prized chert and flint for knapping into arrowheads and spear points due to predictable fracture patterns.
Field identification & locations
Identified by its hard, glass-like texture, sharp edges when broken, and lack of reaction to acid. Commonly found in limestone and chalk formations 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