Flint is an item used to craft basic tools. It can be found on the ground or by mining smooth or gold veined Boulders with the Pickaxe. Flint is not flammable and easy to find on the surface, although eventually it can be used up. More can be found by venturing into a Cave, however.
Flint is one of the first and most needed items in the game and should be sought after as soon as a new game starts. It is recommended to always have at least 2 flints at all times for cases you need to make a basic tool or Spear.
Reign of Giants
In the Reign of Giants DLC, Moleworms will eat any Flint lying on the ground. However, their Burrows can be used to renew flint easily, along with other minerals (excluding Marble and Gems). When dug up using a Shovel, the burrow drops either Flint, Rocks, Nitre or a Gold Nugget. The Moleworm residing there goes off to make a new Burrow.