FL (flawless): This is a perfect diamond
IF (internally flawless): This stone is prefect inside
VVS1 & VVS2 (very, very slightly included): Very hard to see the flaw under magnification
VS1 & VS2 (very slightly included): Hard to see the flaw under maginfication
SI1 & SI2 (slightly included): Flaws are visible under magnificatioin
I1/I2 (included): Flaws are visible to the naked eye Diamonds with a rating of SI2 and better have inclusions that are probably not noticeable to the naked eye. But noticeable or not, the fewer the imperfections, the rarer and more valuable the diamond. So an VVS1 might look the same to the average consumer as an SI1, but will cost much more. Higher clarity does not always make a diamond more attractive, but rather, more expensive. Therefore, unless you are looking for an investment, most consumers opt for a diamond with more carat weight and better color rather than a higher clarity rating.
A diamond’s color is rated through an alphabetical scale from D-Z – with a D rating the best. Only the very best colorless diamonds earn a D rating. The lower the rating the more yellow or brown a diamond is. Most consumers are unable to differentiate between diamonds of only one or two color gradations between them, even when comparing directly next to the other diamond. We recommend comparing diamonds graded by the Gemological Institute of America (GIA) for the most accurate color rating. Other noted grading laboratories are EGL (European Gemological Laboratories) and IGI (International Gemologial Institute)