The stone splitting wedge is meant for splitting big rocks that'd be too tough to move whole. It's the traditional way and still the best and quickest to split large stones from the back.

Drill a row of holes into the rock with a suitable stone drill and insert the wedges into the holes. Then hammer the wedges with a sledgehammer, and the rock will split along the line of the wedges. The bigger the rock, the more wedges you need.