The Old And New Of Cutting Granite
Cutting granite isn't a project for the faint of heart if one hasn't done it before. The need to do so usually comes about as part of a home improvement project, where one wants to install granite tile or granite countertops. Cutting granite tile is one thing, cutting granite countertops is quite something else. If for no other reason, besides the size involved, a mistake in cutting a countertop can be very, very costly. Cutting a granite table top and making a bad cut or causing a piece to break off is a little like carving Mount Rushmore and breaking the nose off Lincoln in the process. Even if repairs can be made, they most certainly will be difficult and possibly expensive.
There are special blades for cutting granite, the most typical being electroplated or brazed blades. Diamond coated blades are also widely used. This brings up an interesting question, that being what did ancient sculptors use to cut granite? They certainly didn't have the blades we have today, having only having copper, iron, or bronze to work with. If you try to cut out granite tabletop with a bronze blade you'll find yourself using up a lot of metal to make a tiny cut in the granite.
Try This At Home? - What was used centuries past, perhaps as far back as ancient Egypt was an equivalent of a diamond tipped blade. In this case the material wasn't diamond, but sand, which is as hard or harder than granite. A copper or bronze blade would be used on top of bed of sand, the sand actually performing the cutting action. Adding water made the cutting even faster, and presumably cut down on the dust as well.
If you're planning on cutting granite for a home project, check with your home improvement center (or look for a video in the Internet) to find out what tools are best as well as what blades to use. One type of power tool is best for cutting tile, while another will be needed for countertops. You can use a wet saw or dry saw technique. The former is messy and needs to be done in a place where water damage won't be a problem, while the latter will cover everything with dust and requires a protective face mask.
Granite, Hard But Fragile - If the granite being cut is for a counter top, and especially if it is a fairly large piece, it needs to be handled carefully. Granite makes a very strong tabletop, but a slab of it is somewhat brittle and can fracture if mishandled. As mentioned above, if it breaks or is cut wrong it can involve quite an expense, so use the carpenter's rule of "measure twice, cut once". In fact, measuring more than twice isn't a bad idea. Once the cut is started, you're committed.
Tools - You might need to rent or purchase a specialty tool. Renting make most sense of course if it's a one-time project. For straight cuts a conventional circular saw can be used as long as one uses a diamond tipped blade, which has to be watered to use the wet method of cutting, which is preferable. Unless you use a specialty tool, granite cutting can be a two person job. Whatever is used for a saw, the cuts and edges will usually have to be polished, and possibly rounded. If that is required, and for countertops it probably will be, a grinding wheel will be required.
Whenever making a cut, patience and care is required, especially if cutting a hole, where it is easiest to fracture a granite slab. No matter what the cut, even a finishing cut, don't forget - “measure twice, cut once”.