Here are some of the diamond basics:
First learn about the Four “C’S” of diamonds and how they affect a diamonds rarity, beauty, and price. Most importantly, unless you are ready to blow thousands of dollars on a diamond that will look like frozen spit, make sure that you absolutely “know your stuff” when it comes to “Diamond Cut” specifically. The degree of precision to which your diamond has been Cut is most crucial in determining how brilliant your diamond will appear to the eye.
The fact that most people want a BIG diamond is fine, just be aware that often times there is a direct consequence to getting a diamond that was crafted to achieve a big carat weight.
By cutting a rough diamond for maximum weight retention, the diamond cutter will sacrifice on the beauty and brilliancy of the stone. Conversely, by sacrificing carat weight and cutting away more diamond from the rough, a cutter will achieve a smaller diamond of infinitely greater brilliance, fire, and scintillation.
Above: Three diamonds of the same carat weight cut to different proportions. Buying the shallow or deep cut will give you less diamond for more money. A poorly proportioned diamond will have less Brilliance, Dispersion, and Scintillation.
I recommend that you see for yourself the difference between a (larger) diamond of poor cut quality versus a (smaller) diamond of ideal cut proportions. The physical, visual difference between the two diamonds is absolutely profound and will certainly be food for thought.
Go to your local jewelry stores and see what kind of quality diamonds they are offering you and what their prices are. Remember to take the diamonds as far away from the countertop as possible. The diamond and jewelry stores all use high intensity halogen bulbs in their showcases that makes all of their diamonds and jewelry look fabulous. This is one of the oldest tricks in the book, so make sure that you give yourself a chance to see how the diamond will actually look in real life lighting conditions….you may be very surprised.
Ask for an INDEPENDENT diamond certificate. This is a diamond grading report issued by a diamond grading laboratory whose only interest is to give you a proper evaluation of the diamonds characteristics. The most recognized diamond laboratories in the world are the GIA and the AGS.
There are other laboratories out there including some “labs” that are used by some jewelry stores whom nobody ever heard of. These labs that have a vested interest in protecting the proprietor, are known to give diamonds better color and clarity grades than they actually deserve, are essentially worthless and quite harmful to you. Make sure that you don’t wind up with a diamond graded by one of these “laboratories” of dubious distinction; you’ll be paying for something that you are not getting.