Up to the fourth century, platinum wedding ring were known only in their rough, or crystalline forms. They came in a variety of shapes, the most common being the octahedron. This was a crystal with eight faces, resembling two pyramids joined at their bases.
The round brilliant wedding rings is by far the most popular shape, and accounts for about 3 out of 4 antique engagement ring purchased today.
Factors important in selecting a fancy shaped GIA Certified Diamond include all of the 4Cs as they apply to the round shape.