Cobblestone Farm

Cobblestone farms are slightly modified on Vanilla X due to TNT duping being disabled. Because of this, automatic cobblestone farms either require a constant supply of TNT to be dispensed into the farm or require a Wither to break the cobblestone.

Semi-Automatic Cobblestone/Stone Farm

https://www.youtube.com/watch?v=GbpQVFLzEBo

Note: It's possible hook this farm up to an automatic skeleton xp farm that uses dogs to kill skeletons in order to repair your pickaxe slightly, however your pickaxe will still end up breaking due to how fast you lose durability in this farm.

Automatic TNT Based Cobblestone Farm

https://www.youtube.com/watch?v=1li1daqIS_k

This is a great design for Vanilla X