Diamonds are an important and expensive purchase. As soon as you start to investigate them, you hear about the "4 C's" : color, clarity, cut and carat (weight.) But the story is much more complex. One issue is the diamond grading report itself and how accurate it is. The Gemological Institute of America (GIA) provides laboratory certifications of diamonds by grading them on the 4 C's. But GIA is not the only grading lab. Certifications are provided by many other labs, some more lenient in their standards than others, resulting in valuations that are much higher.
Diamonds is a vast and complex subject with serious money implications. If you don't have the time to study it, the best you can do is to find an honest and reputable supplier. That's what I do. If you have any specific questions about diamonds, send me an e-mail and I'll try to answer them. If I don't know the answer, I'll ask my supplier, a New York cutter who has been in the diamond business for generations.
Diamonds--Options and Trade-offs
Most people want a large stone, but of course size (carat weight) is a big factor in the price. For traditional diamonds, much is made about the 4 C’s: To illustrate, look at this so-called "gray diamond." It’s a big stone with a relatively small price (2.78 carats, $980 for this ring), as shown in this example:
You can see the trade-off right away--the stone is almost opaque, with none of the sparkle and transparency of a traditional diamond. If you prefer a modern diamond, you’ll find that the bigger and higher-quality the stone is, the higher the price. However, a smaller stone in a higher grade can cost more than a bigger stone in a lower grade . These are the trade-offs.