The 4Cs of Diamonds
explains the 4Cs of Diamonds - cut, colour, clarity, and carat weight - the most important characteristics to understand when making a diamond purchase.
As the largest online diamond retailer, Blue Nile offers the largest collection of the world's finest cut diamonds. Pre-selected for exceptional quality, the cut, colour, and clarity of our loose diamonds are evaluated based on a standardized grading scale. Also, each loose diamond is accompanied by a grading report from either GIA, AGSL, or GemEx, independent diamond grading labs with stringent grading and certification guidelines.
|Grade||Not Carried by Blue Nile||Blue Nile Quality|
|Cut||Fair and Poor||Good, Very Good, Ideal, and Astor Ideal|
|Colour||L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, and Z||K, J, I, H, G, F, E, and D|
|Clarity||I1, I2, and I3||SI2, SI1, VS2, VS1, VVS2, VVS1, IF, and FL|
Price Match Guarantee
If you find a comparable GIA-graded diamond at a lower price, we'll review to match the price.
Diamond Upgrade Program
We offer a lifetime diamond upgrade program on all GIA and AGSL-graded diamonds.