The process can be automated using pistons and a redstone repeater, as shown here: http://www.youtube.com/watch?v=_wLuEO6xOM4&feature=player_detailpage#t=736s h

The process can be automated using pistons and a redstone repeater, as shown here: http://www.youtube.com/watch?v=_wLuEO6xOM4&feature=player_detailpage#t=736s http://www.youtube.com/watch?v=_wLuEO6xOM4&feature=playe... This can produce cobblestone as fast as you can mine it, at a cost of three lava, three iron (for pistons), and a bit of redstone dust (plus items derived from wood, water, and cobblestone, which are all renewable resources) There are other designs which use even less non-renewable resources as well.