It comes in an array of settings and styles though. Below are a few options you can choose when buying a solitaire diamond ring.     When it comes to the cut, the most popular and classic option is the round brilliant cut. It will shine magnificently against any precious metal. Platinum, rose gold, yellow gold, and/or white gold are sure to make a solitaire engagement ring look spectacular. The second most popular diamond cut is the princess cut. A princess cut solitaire diamond engagement ring featuring a four prong cathedral setting looks exceptionally stunning since the square cut gemstone’s straight edges contrast the cathedral setting’s smooth arches.