3-stone engagement rings are a popular and symbolic choice. Typically, in a 3-stone ring, there is a larger center diamond adorned with smaller accent diamonds on either side. The center diamond is said to symbolize the bright future the couple will share together, whereas the two accent diamonds are said to symbolize the past and present. Three-stone rings come in a variety of diamond shapes and sizes. Choose from the vintage oval, opt for the classic round, or the popular princess cut 3-stone ring.