Flint is a sedimentary rock formed from sediment that settled millions of years ago on the bottoms of seas that once covered what is now Ohio. It is a type of the common mineral quartz and one of its microcrystalline forms, with crystals so small they cannot be seen without magnification. Because those crystals are tightly locked together, flint has an even consistency and hardness that make it ideal for creating sharp, durable tools. A colorful Adena cache blade flaked from Flint Ridge Flint was excavated from the Dusthammer Mound in Licking County.