This is a wonderful example of a "Boron Blue" Type II diamond. This diamond shows "No indication of post-growth treatment. Many (most) lab diamonds are treated to make them whiter, or fancy-colored.
I disagree with IGI's color grade here, I believe if we submitted it to GIA, they'd grade it Fancy Light Blue... and charge about $159 for the privilege, so we chose not to. If you purchase the diamond, we will be happy to submit to GIA on your behalf....for $159 and a $250 service fee.
Of course I was kidding about the $250 service charge.
It's a lovely cut - the steps really flash. The faint blue shade is totally apparent in person - and very attractive.