A unique engagement ring design is the tension setting style. Instead of using prongs or a bezel to secure the stone in place, pressure holds it between two halves of the shank. Hidden spring loading and grooves carved into the metal keep the stone still and secure. As a result, it appears to be suspended on its own, giving this ring style a fascinating visual effect. If you love the look of a tension set engagement ring, bear in mind that the process is only suitable for tough stones like diamond, sapphire, ruby, and moissanite. The tension setting process is also completely customized to each stone, so you will need to select your gem first and then have the ring custom-made. Resizing is also very difficult with this setting.