When all of your friends around you start getting engaged, you will hear about the Four Cs all the time. What exactly do they mean?
Cut - Cut many times is lumped in with the shape of the diamond (which we all know are round, oval, pear, emerald, square, heart, triangle... to name a few). Cut actually is referring to how well the diamond is cut which respect to how the light is reflected. The better the cut (not too shallow or deep), the better the light moves through the diamond.
Color - The color is hopefully white. The color is graded from D through Z with D being the closest to white you can get. The white is, again, due to the diamond reflecting the most light.
Clarity - The clarity has to do with any of the natural imperfections of the diamond. This is judged by, once again, how the light passes through the diamond.
Carat - Carat is how the ring is measured and weighed. This surprisingly has nothing to do with the light. While carat is important and many times the easiest thing to judge when your friend gets engaged, cut, color, and clarity play a very important role when determining the value of the ring.
Bottom Line - Good lighting makes every Diamond sparkle!