A 3 diamond ring is often referred to as a trinity ring or a trilogy ring. This type of ring has three stones, usually of equal size and cut. The three stones represent the past, present, and future of your relationship. They may also be two smaller diamonds set around a larger centre stone. This can make the centre stone appear much larger. And finally, it's also common for the outer stones to be of a different kind. For example, you might have a diamond centre stone surrounded by rubies, emeralds or sapphires. You could also have a coloured centre diamond surrounded by white side diamonds. The possibilities are truly endless when it comes to 3 diamond rings.