Minecraft/Gunpowder

Gunpowder is used in crafting and in potion brewing.

Gunpowder is dropped from creepers and ghasts. You can also find gunpowder in most naturally generated chests.

Crafting recipe:

This makes a block of TNT.

When brewed with potions, the potions turn into splash potions, which can be thrown to effect multiple players and/or monsters. This is good for negative potions like poison and slowness.