Granite bloacks are usually cut using a diamond blade in a circular saw.
image by http://www.forgottenstoneworks.com/images/products/web/hand_cut_granite_block_sm.jpg, http://www.sustland.umn.edu/implement/images/stone_walls_1l.jpg
Granite blocks are used in many do-it-yourself projects around your home. Whether outside to complement landscaping or inside to enhance a fireplace or basement room, they have varied uses. Some projects, however, require the blocks to be cut to specific measurements. This is a process once left to professionals, but by using a fairly new tool it can now be done at home.
How to Cut Granite Blocks
Set up the granite block so it is evenly balanced between two sturdy sawhorses. Measure and mark the area to be cut with a pencil.
Insert the diamond blade into the circular saw. Wearing safety glasses and a facemask, begin to cut on the pencil lines.
Sprinkle some water over the cutting area if it starts to smell hot or if you start to see sparks. Simply run your hand under a faucet and drip a little water over the area.
Stop cutting periodically to wipe up any excess stone dust. Too much accumulation of stone dust can mar the cut, because the pencil line may become hidden.
Adjust the block on the sawhorses before completing the cut, so that the cut piece doesn't fall. Or you can ask someone to hold the piece being cut away, provided his or her fingers stay clear of the blade. The person helping should also wear a facemask and safety goggles. Clean the diamond blade after each use. Rubbing alcohol and a clean, dry cloth work best.