Diamonds have four important characteristics, and the quality of each determines the value and the price of each diamond. These characteristics are referred to as the four Cs clarity, carat, color and cut.
Clarity is the measure of inclusions, which are internal defects in diamonds. These inclusions may be crystals of a different diamond or some foreign materials. They could also be tiny cracks or other structural imperfections that look cloudy or white. The clarity of diamonds is determined by the size, color, number, location, visibility and orientation of these inclusions. Clarity grading has become systematic through organizations such as the GIA, or Gemological Institute of America. The systems based the ratings on the inclusions as viewed by a diamond professional less than 10x magnification.
The ratings start at a low imperfect, with the best rating referred to as flawless. Only 20 percent of all diamonds in existence at any one time actually have a clarity grading high enough for it to be used as a gemstone. The rest are used industrially. A large percentage of the diamonds with gemstone clarity still have inclusions that are visible, though some of these...