The shank refers to the band of the ring or the part that actually encircles your finger. Most shanks are rounded but there are also square-shaped shanks and other more creative shapes. The shank can also be of different thickness at either the front, back or sides and can vary in shape and style.
A split-shank refers to a ring in which the shank is joined at the back of the ring. Gradually it starts to split, with the gap widening where it comes to hold the centre gemstone or diamond at its widest point at the front of the ring. See example below.
There are many different options to choose from with this style of ring. There are a whole host of diamond shapes and gemstones that you can set in the centre of the ring. The split of the shank can be quite basic with just a space in between, or it can be twisted. You can also choose to add diamonds and, or gemstones, across the band.
The benefits associated with this ring style are that it will look very glamorous and give the illusion of a much bigger centre stone. Adding small stones, micropave-set, or French-set, will give a stunning and vintage look, maximising sparkle.