Diamond Clarity Refers to the Absence of Inclusions and Blemishes
Natural diamonds are the result of carbon exposed to tremendous heat and pressure deep in the earth. This process can result in a variety of internal characteristics called 'inclusions' and external characteristics called 'blemishes.
Evaluating diamond clarity involves determining the number, size, relief, nature, and position of these characteristics, as well as how these affect the overall appearance of the stone. While no diamond is perfectly pure, the closer it comes, the higher its value.
The GIA Diamond Clarity Scale has 6 categories, some of which are divided, for a total of 11 specific grades.
How did the GIA Clarity Scale come to be?
Like the color scale, GIA's clarity grading system developed because jewelers were using terms that could be misinterpreted, "loupe clean" or "piqué™." Today, even if you buy a diamond somewhere else in the world, the jeweler will most likely use terms like VVS1 or SI2, even if his or her language is French or Japanese instead of English.
What causes inclusions?
Small crystals can become trapped in a diamond when it's forming. Sometimes as a crystal grows it can develop irregularities in its atomic structure.