First, determine your diamond budget. One general rule of thumb when buying a diamond engagement ring is "two months salary." This is just a guideline, it's not carved in stone and your first consideration should be what you can comfortably afford.
Deciding on a diamond carat size is really about striking a balance between size and quality. If she prefers larger jewelry items, and you are working within a budget, we can find a larger size diamond by selecting one which is graded slightly lower in terms of color and clarity. If she adores crisp beauty over visual size stimulation select one of smaller size but higher color and clarity.
Remember that slender fingers make small diamonds look bigger. If she has small fingers, a 1-carat diamond will look proportionately large -- and an even larger diamond may appear stunningly big!
Think about what sort of setting will hold your diamond. You'll have to be sure that the setting you choose is made to fit the carat weight of your new diamond.
A grading report is a "blueprint" of a diamond, it tells you the diamond's exact measurements and weight, as well as the details of its cut and quality. It precisely points out all the individual characteristics of the diamond. Grading Reports also serve as proof of the diamond's identity and value. A certificate is not the same thing as an appraisal.
A grading or lab report describes the quality of a diamond, but it does not place a monetary value on the diamond. An appraisal places a monetary value on your diamond, but not a grading report, and should be completed by a graduate diamond grader.
There are many diamond labs that issue grading reports, but the Gemological Institute of America (GIA) and the American Gem Society Lab (AGS) are the two most widely regarded and recognized diamond grading labs in the world.
Shopping for diamonds with grading reports allows you to make an informed choice about your selections, and to comparison shop. You can compare one diamond with a particular weight and quality with other diamonds of similar weight and quality to determine which is the better value.
If a jewelry store offers to sell you a loose diamond without a grading reports, keep in mind that it means you are buying the diamond based only on the salesperson's claim about its quality, and that a trained Graduate Diamond Grader, like Joe Delagrave, or even other educated graders may disagree with the salesperson's assessment.
