Some truly unscrupulous jewelers target those who want appraisals on diamonds that were given to them as gifts or that were purchased elsewhere. They will try to tell you that the diamond is worthless, or worth less than it actually is worth - and offer to take it off your hands or trade it for a much better diamond, along with the cash to make up the difference. This is called low balling. Get a second, third, and even a forth opinion before taking any action.

Another common dirty trick is to switch the diamond you have chosen and paid for with one of lesser quality and value when you leave it to be set in a piece of jewelry, or leave a diamond ring to be sized. The only way to avoid this is to do business with one trustworthy jeweler. Avoid jewelers that you have not done business with in the past.

There are many more scams that jewelry stores commonly pull on unsuspecting consumers. Just use your best judgment, and purchase your diamonds with the utmost care and consideration.