If you want to cut stone for a wall, or prepare it for dressing, you may be considering using a circular saw. Using the diamond blade on the saw will allow you to get a precise cut, without distressing the stone too much. You need to prepare the stone before cutting.
Step 1 - Mark the Stone
Set up the stone on a pair of sawhorses, and carefully mark out on the stone where you want the cut to be. If you are cutting it to fit in a particular area, make sure that you use a tape measure to get the exact dimensions of the cut.
Step 2 - Cut the Stone
Put on a dust mask to protect you from stone fragments, and use safety glasses. Bring the saw up to the stone, and cut along the mark you have made. Look out for sparks or signs that the saw is getting too hot, and remember to regularly add water to the stone in order to prevent excessive friction. Stop the saw regularly, and brush away stone dust which is forming
Step 3 - Finishing
Before you make your cut stone complete, be sure to bring the sawhorses together, so that the stone doesn't drop between them.