sedimentary
Flint
Cryptocrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically white to grey or brown with a waxy to vitreous luster and conchoidal fracture.
Identified More sedimentary →
Explore Flint 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, typically white to grey or brown with a waxy to vitreous luster and conchoidal fracture.
Formation & geological history
Forms by the replacement of calcium carbonate by silica in chalk or limestone beds over millions of years.
Uses & applications
Historically used for making stone tools and fire-starting; today used in abrasives and decorative gravel.
Geological facts
Prehistoric humans heavily prized flint for its sharp conchoidal edges, which make ideal arrowheads and blades.
Field identification & locations
Identified by its sharp edges, conchoidal fracture, and ability to produce sparks when struck against steel.
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