be careful on your focus, the focus plane seems off a bit on a few, especially the last one,, I like using live view when I do this, and zoom in,, dial in the focus plane, and move the square around to check that the plane is square with the shot.
i did not cut the rocks, i picked them up at a flea market. The cut rock i have are about 1/4" thick so i would think they where done a good "wet" saw with a diamond blade.
