How to make a cobblestone generator in Minecraft
A cobblestone generator gives you endless Cobblestone from one Lava Bucket and one Water Bucket.

A Lava Bucket carries one lava source, a dangerous liquid and an excellent fuel.
As fuel it burns for 1,000 seconds in a Furnace, enough to smelt 100 items.
Fill a Bucket from a lava pool, or from a cauldron fed by dripstone under lava. In a furnace, one bucket smelts a hundred items and leaves the empty bucket. Placed lava flows, burns and sets fire to nearby wood, and water poured over a source turns it into obsidian.
This item has no crafting recipe.
A cobblestone generator gives you endless Cobblestone from one Lava Bucket and one Water Bucket.
Sneak and empty a Lava Bucket on top of the lower gate.
Carry a Water Bucket and several Lava Buckets.
Bought by Villager: Armorer (Journeyman).
It is a top furnace fuel and a way to move lava.
No: only one per inventory slot.
Yes. In a Furnace it burns for 1,000 seconds, enough to smelt 100 items.
Hot Stuff (Fill a Bucket with lava).