A diamond is born - Diamantschleiferei Michael Bonke

The next work step is designing. This task is very important and full of responsibility. The resultof the cutting and polishing is largely dependent on this one small step. While designing, thesupervisor meticulously observes the diamond under a magnifying glass. Then he/she decideswhere the sawing cut can be made. A lot depends on the correct selection of the plane to be cut.It may happen that the cut has to go through an inclusion, which can then be cut away duringthe cutting and polishing process. Furthermore, the sawing cut must be such that after sawing,both halves must correspond to the ideal proportions of the brilliant to be polished. Another veryimportant decision is, whether a large and a small stone should be cut out of the rough diamond orwhether there should be two brilliants of the same size. This is usually a mathematical decision.Example:a 5.0 ct rough diamond is to be sawed. If it is cut in the middle, we will get two raw brilliants ofalmost the same size, i.e. of 2.45 ct each with a yield of 42%; this will result in two diamondsof 1.03 ct each. If the saw-cut is asymmetrical, then we would get one rough diamond of 3.0ct and one of 1.95 ct. These two cut brilliants would then have a weight of 1.26 ct and 0.82 ctrespectively. The sales returns of these two stones would be much lower than two stones of onewhole carat each.Another example:a rough diamond of 4 ct is sawed. If cut in the middle, it will result in two raw stones of 1.98 ct each,i.e. two brilliants of approximately 0.83 ct each. If the cut is asymmetrical, we will get a 2.5 ct stoneand a 1.46 ct stone. These two stones will yield two brilliants of 1.05 ct and 0.61 ct respectively.In this case, the asymmetrical sawing cut is more advantageous, because one diamond of onewhole carat (1.05 ct) and the other of a good half carat (0.61 ct) are worth much more than twodiamonds of good three-fourths of a carat (2 x 0.83 ct). So, such stones are cut asymmetrically.Even in case of very small stones, which yield only 0.01 ct after being cut and are barely the sizeof a pinhead, the designing must be done with great care. A careless designer can often cost thepolishing plant the entire profit for that stone.