Help with diamonds!!

[anascimento]

Can anyone tell me what are good measurements for a princess cut diamond..
I''m confused on the table, depth and girdle.. I don''t understand how one can know what makes it a good cut and bad cut. I saw a few charts online with table sizes and depth but then when I search online the numbers don''t make sense. Is there a relationship between the table and the depth? are they completely independent or no? how about all the other things? symmetry, polish etc.
the only things clear to me is color, clarity and carat.. lol
help! we dont have to get scre..ed

 

[JulieN]

For charts, this is a good starting point: http://diamonds.pricescope.com/fnc1.asp But it should be used judiciously, because this chart was made quite a long time ago, and (manufacturing-side) we have better technologies that aid in making nice stones and (consumer-side) we have more efficient ways of finding nice stones.

Strictly speaking, there is no relationship between table and depth, and there is a no relationship between symmetry and polish (except maybe if it were a particularly difficult piece of rough to work with?)

However, there are some subtler details or trends that you may pick up on, but remember that there are always exceptions to such trends, especially theoretically.