Flint
“Spark of civilization”
Sedimentary
Flint is a hard, microcrystalline variety of quartz (chalcedony) found as nodules in chalk and limestone. Its ability to produce sharp edges when fractured and sparks when struck made it arguably the most important rock in early human history.
Composition
microcrystalline quartz (chalcedony), traces of organic matter
Where Found
Norfolk (England), Denmark, Flint Ridge (Ohio, USA), Belgium
Mohs Hardness
6.5-7
Fun Fact
Flintlock firearms, used from the 1600s through the 1800s, relied on flint striking steel to ignite gunpowder — hence the name.
Test Your Knowledge
How do flint nodules form inside chalk and limestone beds?
Related Specimens
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