Diamond is the hardest material known. This hardness gives it the superior performance of cutting any other material. PDC is extremely important for drilling because it aggregates tiny, cheap man-made diamonds into relatively large, mutually-grown randomly oriented crystal masses, which can form useful shapes called diamond tables. The diamond table is the part of the cutter that touches the formation. In addition to hardness, PDC diamond countertops also have the basic characteristics of drill tools: they are effectively combined with tungsten carbide materials that can be brazed (attached) to the drill body. The diamonds themselves are not glued together, nor can they be joined together by brazing.