I am planning to do a ruby ring with an oval ruby and two small side diamonds. My original thought was to go with 2 Brillant Round diamonds on the sides. My jeweller suggests two custom cut half moon shaped (I assume brilliant cut) diamonds on the sides. My question is: do the diamonds lose most of their sparkle/brilliance if the shape is no longer round because the other halves of the diamonds are no longer there to reflect "light return"?