The center stone is a 2.01 Cushion Brilliant/G/IF. Designed by Gary Friedman and Mark Turnowski of Engagement Rings Direct. The halo pave and the ring pave are a little different. Apparently, these men know how to design stunners!  Get ready to gasp (in a good way)!

Im estimating it's about 1-carat, F-color, VS2 center stone in a custom diamond setting...great photo