Clarity

Perfection in a diamond is a rarity. Diamonds are graded under 10 times magnification to determine their clarity. Clarity is the measure of inclusions or imperfections.  Clarity is graded on "completely flawless" to "noticeably imperfect" diamonds.  The fewer and smaller the inclusions are, the less likely it is that such miniscule imperfections will interfere with the passage of light through the diamond, therefore leaving you with a beautiful and radiating stone.  A diamond that is free of both inclusions and surface blemishes is indeed a rarity and therefore more valuable.