I am quite puzzled why a wonderful high RI design like the Kiev Triangle intended for RI 2.16 would be the Grand Master Stone in 2018 using Feldspar family materials. Frankly, by listing the CZ angles and an RI of 1.557 material, you have wasted a 12 mm Feldspar stone. The resulting stone windows and looks so bad most people will not want to show this stone to anyone unless they place high in their score. Even if one transposes the angles and “optimizes” this design, it’s not very nice performing. Large number of facets hides performance to a degree, but a better material should have been chosen with an RI closer to CZ.