sedimentary
Flint
SiO2 (Microcrystalline Quartz)
AI-generated identification · may be incorrectMohs hardness of 7, typically grey or dark brown to black, waxy to vitreous luster, conchoidal fracture with no cleavage.
Identified More sedimentary →
Explore Flint in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness of 7, typically grey or dark brown to black, waxy to vitreous luster, conchoidal fracture with no cleavage.
Formation & geological history
Formed through the chemical replacement of calcium carbonate in limestone or chalk by silica-rich solutions over millions of years.
Uses & applications
Historically used for making stone tools and sparking fire; modern uses include abrasive grits and decorative gravel.
Geological facts
Flint played a vital role in human prehistory due to its ability to be chipped into extremely sharp edges through knapping.
Field identification & locations
Identified by its distinct conchoidal fracture, sharp edges, and ability to scratch glass; commonly found within chalk or limestone 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