Diamond prices are determined first by adding the cost of the rough diamond, the cost of cutting the diamond, and all other costs necessary to turn the rough diamond into a marketable diamond. Depending on the importance of the diamond, an independent company may be called in to certify the grade of the diamond based on color, cut, clarity, and weight.

At this point, the diamond becomes more expensive each time it changes hands, until it finally reaches a retailer, where the price is raised a bit more. Before reaching the retailer, however, the diamond must travel from the mine, to the cutter and polisher, to the independent grading company, and then to the Primary market. Once it has reached the primary market, it will be purchased by diamond dealers and wholesalers, and from there it will be sold to retailers.

As you can see, the earlier you can purchase a diamond in the process, the lower the cost of the diamond will be but not the value. The value is based on what the diamond will sell for in the market place through a retailer.

If you own a diamond, and you have no idea how much it is worth, you can have it appraised, but the appraisal may not be accurate. You will be better off obtaining a certificate through GIA - Gemological Institute of America. With the information on this certificate, you can use a cutter's guide to accurately determine what your diamond is worth.

First, only deal with reputable jewelers, and when you find a reputable jeweler, stick with them. Avoid buying diamonds or other jewelry from jewelers that you have never dealt with before in the past. Ask to see the certificate for the stone. If no certificate exists, walk away.

After purchasing a diamond, take it to another jeweler for appraisal. In fact, take it to two or three other jewelers for an appraisal to make sure that the appraisals are all fairly close. If you find that you have purchased a fake diamond, you may be accused of making a switch when you return to the store of your purchase; therefore, it is important to have a certificate for the diamond. No two stones are alike.

There are also many diamond price calculators available. These can be found on the Internet, and many diamond dealers use these as well. You must realize, however, that before you can accurately price a diamond, without a Diamond Grade Report, you need to know quite a bit about diamonds, such as different cuts, clarity, color, and weight and how each of those aspects adds to the value of a diamond, or decreases the value of the diamond as the case may be.

Again, you will be better off if you get a Diamond Grading Report on the diamond, and use that information to look up the price in one of the guides that the diamond cutting industry uses. This will give you the most accurate value of the diamond in your possession, or of the diamond you are considering purchasing.