A Detailed Look into Diamond Cutting

An uncut diamond is normally sawn or split into two or more stones as decided by the diamond cutter. It just takes a simple error here to completely ruin a valuable stone and turn it into nothing but dust. Now you can understand the hypertension rate among diamond cutters and airport controllers.

Once a rough diamond is split, the diamond cutter then decides how the stone will be laid out and cut. This operation means that a certain portion of the diamond will be ground off and lost and so this cut plan becomes an important step in finishing the final stone.

The first step taken by the diamond cutter is to girdle the diamond. This process of girdling establishes the size of the stone and puts a "waste" on the stone. If a stone is poorly girdled, it will not appear completely round when viewed with the jeweler's loupe or microscope. A round brilliant cut stone should be perfectly round and symmetrical.

Other mistakes in girdling will produce flaws that manifest themselves as a razor thin girdle which is prone to chipping or breaking (even though diamonds are extremely hard, they are brittle and can be chipped or shattered in thin areas). A too thick girdle takes away from the brilliance and fire of a stone and indicates a poor job on the part of the diamond cutter.

A diamond cutter cuts (in a brilliant cut) 58 facets all done on exact angles in exact positions in order to let the diamond reflect as much light as is physically possible. The brilliant cut stone has 16 facets on top and 16 facets on the bottom that reflect the light and give the stone its cut. Each facet is cut on a unique angle and is exactly straight when viewed with other facets in order to maximize light reflection.

When you view a brilliant cut stone, around the table of the stone you'll see the kite and the topmain facets. These facets are the areas that allow the light to come through to the viewer. Beneath these you have eight star facets and then 16 upper girdle facets before you reach the girdle itself. Beneath the girdle you have an additional 16 lower girdle facets. All these ancillary facets contribute to the light reflection through the kite and top main facets and the table portion of the stone.

What is the advantage of the 58 facet brilliant cut stone? What does one expect to see when viewing a diamond? There are two qualities that make a diamond attractive to the eye. The first one is known as life and indicates the amount of light that is reflected back from the diamond to the viewer. The second quality is known as fire, which is an indication of the amount of refraction from the facets and split into colors as in a prism effect.

Besides the 58 facets, a number of other factors contribute to the perfectness of a brilliant cut stone. The stone's table should be 53% of the area of the stone. While the ratio between the depth of the stone or the length of the stone if you view it from the side, to the spread of the stone which is the maximum diameter of the girdle, this ratio should be 60% depth to spread.

The angles on a stone must be cut exactly to critical angles. Any deviation will produce a less than perfect reflection of the light waves entering the stone. A jeweler will have special gauges to measure these angles. These gauges are available but they are expensive. Or one can buy a loupe that is marked with angle markings. When angles are viewed through this loupe, they can be accurately measured.