It might not be common knowledge but diamonds can be cut in any shape or size, round, princess, emerald, cushion, pear, oval just to name a few and consequently each shape will sparkle differently.
Nothing sparkles more than a brilliant round diamond, simply because it has 57 facets (sides) to the diamond, more facets than any other shape of stone. That is what gives the round diamond the sparkle.
The princess (square) diamond has 52 facets so sparkles almost as much as the round, then comes the various other shapes, cushion, marquise, radiant etc.
The diamond which sparkles the least is the emerald cut which only contains 17 facets. So little is its sparkle that you can see straight through the diamond like a piece of glass. However, with this unique ‘lack of sparkle’, there is nothing more classic than this stone, showing its true elegance through the low number of cuts of the diamond.
We can’t advise you which diamond your partner would like but one thing is for certain, everyone loves their sparkle!