The smart groom-to-be does his research before buying his fiancée a diamond ring! There are more styles and cuts to choose from than ever before. It's not enough to be educated about the four Cs of diamonds - cut, color, clarity and carats. Now there are all types of diamond cuts and settings to choose from.

The most popular style is still the round brilliant. It's one of the earliest cuts ever developed and now relies on precise mathematical equations to create a stone with fire and brilliance that the earliest gem cutters could only have dreamed of.

But many brides want something completely unique. There are many traditional cuts to choose from. A pear-shaped is just that - wider at one end than the other. Or she can choose an oval, emerald or heart-shaped diamond. There are other cuts with unique faceting, such as the square princess-cut diamond.

Some cuts are patented, like the elongated Ashoka diamond or the Asprey & Garrard Eternal cut diamond. Other branded and patented cuts include:

Elara - a square-cut diamond with rounded corners

Asscher - a square diamond with rounded facets that gives an unusual complexity to the diamond

Couples diamond - this diamond is faceted to reveal either a circle of hearts or arrows inside. It's a truly unusual diamond that requires precise cutting for the image to appear properly.

The price of a diamond increases exponentially with its carat weight. A one-carat diamond costs much more than 10 10-point diamonds and a two-carat diamond costs more than twice as much as a one-carat diamond (given equal quality in other areas).

One way to enhance a ring is with embellishments such as baguettes or trillions. A baguette is a small emerald-shaped diamond that can be placed on either side of the main stones and a trillion is a triangle-shaped diamond that also is a good enhancement to the center stone.