When choosing to make a diamond purchase you have several choices to make. You must consider the size, weight, color, location from where it was mined. One of the first decisions you will need to make is the type of cut.

When you hear people talking about heart diamonds, princess diamonds, round diamonds, or marquise diamonds. These terms all refer to specific "cuts" of diamond, more simply they are the shape the diamond is cut into. depending on the type of cut and quality the amount of sparkle the stone has will vary widely.

Obviously once a diamond is cut, it is generally not practical to recut it into a different style because you lose a substantial amount of the diamonds size. Additionally, the equipment and skill required to cut diamonds makes the cost of cutting a diamond a substantial portion of what you pay for. Therefore the value of a diamond in terms of both popularity and price depends on the quality and type of cut.

The most popular is the round cut diamond. As the name suggest this refers to when diamonds are cut to look like circles. Generally this type of cut will be the most "brilliant" or radiant diamond cut. There are some minor variations in this style but in general a round brilliant cut diamond will have 58 facets. This cut of diamond is popular in engagement rings as both a solitaire or part of a multi-stone arrangement.

Princess cut diamonds are also very popular. This cut is similar to the round cut except the top or table of the diamond is cut into a square rather than a circle. Though both cuts can be very brilliant a Princess cut diamond that has the same diameter as a round cut diamond will way quite a bit more. Typically a princess cut diamond will be cheaper though because less of the raw diamond is lost during the cutting process. This makes it a popular shape among diamond cutters.

Least expensive is an emerald cut diamond which gets its name because the cut is identical to the most common cut for emeralds. With this cut the diamond is shaped like a rectangle with bezeled sides. Despite being cheaper this type of diamond cut is considerably less popular than round or princess cut diamonds.

A heart cut diamond is relatively new option. It is similar to a pear shaped diamond, and in fact the process of cutting a diamond into a heart shape involves cutting into the pear shape and then creating more cuts on the rounded side. This cut is perfect for romantic occasions because of the emotional symbolism of the heart.

Another common cut that you are likely to encounter is the marquis cut diamond  which looks like an oval. If used in a ring it can make shorter fingers appear longer. Typically it is found as a solitaire or as the centerpiece in a multi-stone arrangement.

Of course there are many other cuts that I haven't covered, but these are the most common cuts you will encounter when shopping for diamonds.

As I mentioned earlier the quality of a cut can vary widely, so even if you have decided on a particular cut you should look at several diamonds in that cut from several different sellers to find the best one.