sedimentary
Flint
Microcrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically dark gray or black with a waxy 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 dark gray or black with a waxy luster and conchoidal fracture.
Formation & geological history
Forms via chemical replacement of limestone or chalk by silica-rich groundwaters in marine environments.
Uses & applications
Historically used for making stone tools and fire-starting; currently utilized in abrasives and decorative gravel.
Geological facts
Prehistoric humans prized flint for its sharp conchoidal fracture, making it ideal for arrowheads and blades.
Field identification & locations
Identify by its conchoidal fracture, waxy luster, and ability to spark when struck against steel. Found globally in chalk formations.
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