Diamond coated tile/stone blade (expensive - $50-100, but worth it when I have to cut stone pavers for my walk - you can rent the saw but will be charged for wear) - cuts only straight lines tho... for curves, you cut a series of straight lines up to your curve (like a feather board), break off the small pieces & smooth the edge with grinder. Or may be you can find a 2" diamond coated drill & cut the circles in a drill press.
For a cheap & tedious way - try using a diamond bit in a dremel. It will cut stone, but depending on thickness may take forever!
80 gal FW with 30 gal DIY wet/dry/sump.
9 fancy golds, 1 hillstream loaches, 1 rubber-lip pleco (C. thomasi), 3 SAEs, small school of white cloud minnows, planted.