cen·ter stone | sen-tər stōn
A precious or semi-precious gemstone placed within an engagement ring's head, as the focal point
Many gemstone and diamond rings, pendants, and brooches have multiple stones. For these jewelry pieces, the main stone in the center - which is the focal point of the piece of jewelry - is called the center stone. Engagement rings with center stones are very popular in the United States. Though there may be only one large diamond in an engagement ring, it's common for that center stone diamond to be surrounded by smaller diamonds, or for the engagement ring band to be adorned with diamonds on both sides, or throughout the band as an eternity band. Currently becoming more popular in the US is the up and coming trend of center stones in engagement rings being accented with other precious gemstones, such as sapphires, rubies, or emeralds. In a cathedral setting engagement ring, the center stone is the larger, raised diamond that appears in the middle of the three stone ring.