What's difference Cubic Zirconia Stone both Princess Cut and Radiant cut 

Both the Princess and the Radiant are beautiful gemstones cuts, especially for engagement rings. Some would even say they are very much alike given their squarish shapes. If you’re trying to decide which of the two best suits your choice of CZ jewelry, there are a few basic questions you will need to ask.

Because of its brilliant facets, the radiant cut reflects light better than the princess cut and therefore has better sparkle. The radiant cut was invented by Henry Grossbard in 1977, he took the basic shape of the emerald Cut and added more brilliant facets to develop the radiant cut.The radiant cut is better suited for those with active lifestyles because it doesn’t feature sharp corners that can get caught or chipped off with rigorous activities. It is also the best cut for multiple-prong settings because of its cut corners. On the other hand, the princess cut features a geometric shape that makes it ideal for those who prefer channel settings. Princess cuts are the very pointy corners.Everyone has their preferences. You are a fan of radiant cut gemstone, you do like it. Maybe you fall in love with princess cuts stone. Both two cuts usually are set to engagement ring as center stone. 

                                                       
                 gemstones princess cut                  squarish radiant cut          rectangular radiant cut
                        gemstones  princess cut                    gemstones squarish radiant cut           gemstones rectangular radiant cut

since it is a square, but is very different from princess/radiant cuts. And obviously all of this is personally opinion and ultimately you should pick whatever makes you happy.