How a diamond has been cut, polished, and to what proportions, are of utmost importance - since these factors determine the life, brilliance, and luster of the diamond. If these cutting factors fall below standard, the appearance of the diamond will be adversely affected. The brilliant (or round) cut is the most popular, but other exquisite cuts are also highly prized.
The weight or size of a diamond is measured in carats (ct). A carat is 0.2 grams and there are 100 points (or 200 milligrams) per carat. With an accuracy of 1/100,000 ct, the I.G.I. scales provide a highly precise diamond weight and this weight is specified on the Diamond Report to two decimal points.
In order to grade the clarity of a diamond, it is necessary to ascertain the number and nature of any inclusions in the stone as well as their size and position. This analysis is carried out using the IGIscope and a loupe 10x under the experienced eye of laboratory gemologists. A diamond is said to be "internally flawless" when it presents no internal defect under 10x magnification.