Flint

Flint is found by mining gravel. There is a 10% chance that a single unit of flint will drop instead of the gravel block. It is possible to farm flint by placing stacks of gravel and mining them down; this is a one-way process, there is no way of turning flint back into gravel.

Harvesting gravel by making it fall on a block such as a torch will yield flint since 1.9 Prerelease 6. (Confirmation needed: could not reproduce in SMP)

Trivia

 * After the 1.3 update, finding flint is more common.
 * It takes 4 1/2 wooden shovels to convert 24 blocks of gravel into flint. Using this result, it should take 12 wooden shovels to convert one stack of gravel into flint.
 * In the 1.0.0 Full Minecraft Release version, gravel will not produce flint if it has already been mined and is already in your inventory.

Feuerstein Flint/es Silex Kovakő Kiezel Krzemień Кремень Flint/ch