Round brilliant cut diamond

[candy23]

I planning to buy a round brilliant cut diamond - would like to know the parameter to analyze the diamond cut proportion - need advise??

[oldmancoyote]

I assume you are referring to a colourless/near colourless stone - coloured stones are quite rare in rounds, and pretty much you take what you can get (cut will have been used to maximise colour, rather than other aspects).

Even with colourless/near colourless stones, the most you can do is weed out likely duds if all the information you have is what is printed on a grading report. Once you have done that, you need to get more information on the stone which requires someone having access to it - the best way to do it is to choose the dealer before you start selecting the diamond. Use recommendations from friends and family (and trusted internet sources), but also give dealers a call and see how well they respond to your questions.