sedimentary
Chert
Silicon dioxide (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, waxy luster, microcrystalline quartz structure, conchoidal fracture, and variable colors including grey, white, and brown.
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, microcrystalline quartz structure, conchoidal fracture, and variable colors including grey, white, and brown.
Formation & geological history
Formed through the chemical precipitation of silica from seawater or the replacement of limestone by silica-rich groundwater during ancient marine deposition.
Uses & applications
Historically used for making stone tools and arrowheads due to its sharp conchoidal fracture. Modern uses include abrasives and aggregate.
Geological facts
Chert nodules are frequently found embedded in chalk or limestone formations. Ancient humans heavily favored fine-grained varieties like flint for knapping weapons.
Field identification & locations
Identify in the field by its distinct waxy luster, extreme hardness, and sharp conchoidal edges. Commonly found in sedimentary basins 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