When buying diamonds, be aware that most consumer name brand frqnchises will scam you. To protect yourself, you need to things: (1) a price sheet like from Rapaport and (2) an understanding of this diamond grading works. The most common craziness I saw while diamond shopping in USA was low quality diamonds but with large carat counts being sold at huge markups. Another thing to look out for is cheaper certifications; some certifications are much stricter on grades than others. GIA is reliable, look for it. You also need to read the etching of the diamonds cert number on the physical diamond yourself; in one instance a friend had his diamond swapped by the dealer, and proved it thru the physical etching.