The 4 C's What kind of diamond should I buy

Beloved...Bejeweled...Be Careful:

Quality and value are important when buying an item as important as a Diamond. Diamonds come in all shapes, sizes & quality. Anyone shopping for a diamond enters a world full of unknowns. How do I know what to look for? How can I tell a good diamond from a poor one? How do I know whether the person I am buying from is telling me the truth?
Diamonds are unusual in that they have a recognized language for quality ranking. While other grading systems exist, the most widely used is the one taught by and used by the Gem Trade Laboratory of the Gemological Institute of America (GIA), started in the 1950's.
To establish a diamond's quality, we examine each of the 4"C's" - Cut, Color, Clarity, and Carat weight. The combination of the "4 C's" determines the value of a diamond. You as a consumer have one additional "C" to consider - Confidence, you should have confidence in the person you are buying from.
We urge you to take a tour through our 4C's, even if you have done so at other sites, you might learn something new.
CUT - The better cut a diamond, the more brilliance
COLOR - The less color in a diamond, the more beautiful
CLARITY - The less inclusions in a diamond, the more valuable
CARAT WEIGHT - The larger a diamond, the rarer

Many people ask: Which "C" is the most important?

A diamond's quality depends on a combination of all four "C''s". However, we believe the most critical of these is the cut, more than any other factor, it determines the brilliance and beauty of a diamond. A well cut diamoond can hide inclusions or give a whiter, more brilliant appearance.