(THIS IS OUTDATED)The Stone crusher is the slowest crusher of all, however to increase crushing speed it can be upgraded to the Copper Crusher. It's used for making ore dust, which is in turn used in the crafting of alloys or to simply duplicate the ore yields.
A stone crusher takes 1 minute to crush one ore into dust.
This means that one coal can be used to crush only 1 ore, and that 64 coal are required to crush an entire stack of ore.
Crushing a full stack of ore takes 1 hour using this crusher.