IF → Internally FlawlessInternally Flawless: No internal or external imperfections. Very rare
VVS1, VVS2 → Very, Very Slightly IncludedVery difficult to see imperfections under 10x magnification. An excellent quality diamond.
VS1, VS2 → Very Slightly Included Imperfections are not typically visible to the unaided eye.
Less expensive than the VVS1 or VVS2 grades.
SI1, SI2, SI3 → Slightly Included Imperfections are visible under 10x magnification, and may be visible with the unaided eye.
A good diamond value.
I1 → IncludedThis grade of diamonds will have minor inclusions that may be visible to the unaided eye.