Example of natural "frost-pitting" in flint.
Licence: Attribution 4.0 International (CC BY 4.0)
Credit: Example of natural "frost-pitting" in flint. Wellcome Collection. Source: Wellcome Collection.
Licence: Attribution 4.0 International (CC BY 4.0)
Credit: Example of natural "frost-pitting" in flint. Wellcome Collection. Source: Wellcome Collection.