The greater the diamond's clarity, brilliance, value and rarity, the higher it is on the Diamond Quality Chart.
Diamonds with "inclusions" or flaws which are virtually invisible to the naked eye lessen the value of the diamond. Flawless stones have no inclusions on the surface and are at the peak of the chart, FL-IF. Diamonds with very, very small inclusions are graded as VVS1 or VVS2. The larger the inclusion, the lower the grade and the less rare the diamond.