sedimentary
Flint
Microcrystalline quartz (SiO2)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically grey, brown, or black 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 grey, brown, or black with a waxy to vitreous luster and conchoidal fracture.
Formation & geological history
Formed through the chemical replacement of calcium carbonate by silica-rich solutions in chalk or limestone beds over millions of years.
Uses & applications
Historically used for making stone tools and fire-starting; currently utilized in landscaping, ceramics, and abrasives.
Geological facts
Flint played a critical role in human technological development during the Stone Age due to its ability to be chipped into extremely sharp edges.
Field identification & locations
Identify by its conchoidal fracture, smooth weathered cortex, and ability to spark when struck against steel. Found globally within chalk and 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