Natural diamond die produce the finest quality wire and are the most expensive. The core of a natural diamond die is made using industrial grade diamond stones that are mined from the earth. Each stone is selected, cut and sorted into a workable size. Natural diamond dies are mostly used for final sizes and for producing very fine wires. They are also used for producing wires of excellent surface finish. The downside with natural diamond dies is that they wear unevenly and this has an adverse effect on the useful life of the die. The uneven wear is because of undetectable defects in the natural diamond stone.