The 4 C’s – Clarity
Clarity refers to the internal and external imperfections (inclusions and blemishes) of a diamond. Diamonds from natural sources are subject to individual flaws including trace minerals, cracks, carbon and scratches. While these flaws are often not visible to the naked eye, they affect the light reflecting qualities of the diamond which affects the overall brilliance.
The inclusions in a diamond range from white and black dots on the surface of the stone to small cracks within in the stone and crystalline growth within the diamond. Most of the flaws of a diamond are tiny imperfections that do not affect a diamond's brilliance as seen by the unaided eye.
But a diamond without such characteristics is called flawless and is the rarest kind.
Specific criteria is used to differentiate between grades on the GIA grading scale for diamond clarity. Diamond clarity is classified as: Flawless, IF, VVS1, VVS2, VS1, VS2, SI1, SI2, SI3, I1, I2 and I3
FL: Completely flawless.
IF: Internally flawless; only external flaws are present, which can be removed by further polishing of the stone.
VVS1: Very Very Slight Inclusions. Only an expert can detect flaws with a 10x microscope when viewing the bottom of the stone.
VVS2: Very Very Slight Inclusions. Only an expert can detect flaws with a 10x microscope when viewing from the top of the diamond.
VS1-VS2: Very Slight Inclusions. One can see flaws with a 10x microscope, but not easily.
SI1-SI2: Slight Inclusions. Inclusions are easily visible under 10x magnification. These stones are often "eye-clean".
SI3: Slight Inclusions - This grade is only recognized by EGL and is not recognized by the GIA or other gemmological institutions and may be graded by GIA as either SI2 or I1. SI3 diamonds never have any black inclusions or cracks visible to the unaided eye, but may have some very minor white inclusions which can be seen.
I1: Inclusions visible. An I1 clarity graded diamond will have a visible flaw which can be seen with the unaided eye, but most of the time will only have one major flaw which will not be too obvious.
I2-I3: Inclusions high visible. These diamonds will have inclusions visible to the unaided eye and will have many black spots and appear cloudy.