The clarity scale for diamonds tiers from perfect (no internal or external imperfections seen beneath 10x magnification) to blanketed (seen flaws without magnification). The grades, in ascending order, are wonderful (FL), Internally faultless (IF), Very, Very slightly included (VVS1 and VVS2), Very barely protected (VS1 and VS2), barely included (SI1 and SI2), and protected (I1, I2, and I3).