Quartz is very similar to granite, being composed of minerals and additives and compressed into a solid material. Both quartz and granite are some of the hardest substances on earth and popular for kitchen and bathroom countertops. Because of the strength but brittleness of quartz, it cannot be cut with any plain saw or a tile saw. Just like granite, you must use a wet saw with a blade outlined with one of the only known materials harder than these masonries--diamonds.
Measure out the cuts that you need to make with a tape measure. Use a color of chalk that will be visible against the quartz to mark the planned cuts. Spray over the chalk lightly with hairspray to set it; you can easily wipe this away later with a damp rag.
Put on a pair of safety glasses and heavy work gloves. Cover your mouth and nose with a paper mask or respirator, since particles may be thrown off and you do not want to breathe them. Fill the reservoir of the diamond bladed wet saw with plain water.
Position the quartz on the platform of the saw and adjust it so that the blade is lined up with the first chalk line. Do not touch the blade of the saw with the quartz yet. Turn the saw on low and allow the blade to run through the water several times so that it is damp; turn the saw up to medium.
Place your hand on the top of the far outside of the quartz, well away from the blade of the saw. Use this hand to guide the quartz against the saw blade; push the quartz firmly against the blade until the cut is finished. Make the rest of the cuts that you need.