Diamond Education - Clarity
IF/ FL: There are no blemishes or inclusions in flawless and internally flawless diamonds.
VVS1/ VVS2: Very very slightly included diamonds have minor inclusions difficult for even an experienced grader to see under magnification and almost impossible for most common people to see.
VS1 / VS2: May contain small unclear clouds, crystals and even sometimes feathers when placed under magnification.
SI1/ SI2/ SI3: contains noticeable clouds, feathers, included crystals, seen under magnification and can be seen by the common person.
I1 / I2/ I3: Diamonds contain large feathered and clouded inclusions that most common people can see imperfections without magnifying.