Anyone know about diamonds?

Brilliant round cut will give you the most sparkle. Theoretically, all of the light that goes into a brilliant cut diamond will exit through the top. This is the diamond our physics professors always recommended when we studied optics. Here is a wiki with more info about the brilliant round cut than I care to write.

On top of this you want to look at the quality and clarity of the diamond. The diamond game is all about quality over quantity. A large diamond is really not worth the money if it has too many inclusions and other quality reducing factors.

 

Agreed 100%