sedimentary
Flint
SiO2 (Cryptocrystalline Quartz)
AI-generated identification · may be incorrectHardness of 7 on the Mohs scale, typically brown, gray, or black, waxy or vitreous luster, microcrystalline structure, conchoidal fracture with no true cleavage, specific gravity of 2.60 to 2.65.
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 brown, gray, or black, waxy or vitreous luster, microcrystalline structure, conchoidal fracture with no true cleavage, specific gravity of 2.60 to 2.65.
Formation & geological history
Formed as nodules or masses in sedimentary rocks such as chalk and marine limestones through the replacement of calcium carbonate by silica-rich solutions diagenetically.
Uses & applications
Historically used for making stone tools, weapons, and fire-striking implements; modern uses include landscaping and as decorative or educational specimens.
Geological facts
Flint breaks with a characteristic conchoidal fracture, producing extremely sharp edges that made it invaluable to early humans for tool-making.
Field identification & locations
Can be identified by its conchoidal fracture, waxy luster, and high hardness capable of scratching glass. Commonly found globally in chalk formations and limestone deposits.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary