Six Claw
She's classic, modern, and a bit of a traditionalist. She might not wear any jewellery currently, and if she does, it's understated and timeless. The most traditional yet contemporary look is a solitaire (single stone). If you want a little extra sparkle, consider shoulder diamonds (smaller diamonds down the band).
Four Claw
She's modern and loves simplicity. It creates the shape of a princess cut diamond (square) but has the sparkle of a round brilliant diamond (circular). This design isn't as well suited to the woman with a very active or physically demanding lifestyle, as four claws aren't as secure as six.
Cluster or Halo
This refers to a centre diamond surrounded by smaller ones. These rings can have either a modern or very classic look, depending on how they are set. It is also a great way to get a larger look for a lower price. When combined with details such as millgraining (small metal beads) or filigree (fine ornamental metal work), clusters can have a timeless "heirloom" appearance.
Princess Cut
A princess cut diamond ring features a square diamond, which is the second most popular choice after a round brilliant. These diamonds are great for modern women who still want the traditional "engagement ring" look. They can be set in a number of ways and can be a solitaire, solitaire with shoulder diamonds, or form a part of a halo ring.
Fancy Cut
Fancy cut diamonds come in a plethora of shapes and are often the best choice for a more antique or "old-worldly" design. These diamonds are often less expensive then the round brilliant and princess cut as the demand is not so great. Make sure you explore the options available in fancy cut diamonds before you make a decision!
Three-Row or Trilogy
These rings feature three diamonds or gemstones in a row, either almost the same size, or with a much larger centre diamond and two smaller flanking stones. These can either be modern or classic, and are a good choice if you want to include other coloured diamonds or gemstones.