Things You'll Need
Instructions
Don your safety gear. At a minimum, you should wear safety glasses and a particulate mask. Gloves and a full mask can protect your skin from cuts.
Wrap the quartz crystals in a towel. Use old towels because they will likely tear because of the sharp crystal edges.
Place the wrapped crystals on a hard surface such as a concrete sidewalk or patio. Choose a spot that can withstand a strong force from a hammer and where you are not concerned with scratching the surface.
Hit the crystals with the rock hammer. To create the small shard size, you will likely need to strike the crystals repeatedly. If necessary, unwrap the crystals after your initial break and re-wrap the large pieces to repeat the process. The natural fracture of the rock creates smaller shards of quartz as you continue to break the crystals. The benefit of using the rock hammer is that you can control the force that you exert on the crystals, thus controlling the size of the shards.