I recently sold a beautiful engagement ring. My customer elected to purchase the center diamond for the ring from a well know national jewelry website. In situations like this I follow the Golden Rule, set my competitor's diamond in my ring, and thank my client for their business. In today's economy I am grateful for whatever business I am given, even if I only sell half of the ring.
A few weeks later I received an email from my client saying his proposal was a big success and that his fiance' loves the ring. He did say, however, that he and his fiance were a little disappointed with the quality of the center diamond. It seems that when they look closely at the diamond they can see a few small inclusions (flaws) with their naked eye. According to the national jewelry website a diamond with the clarity grade assigned to their diamond should not have eye visable inclusions.
This situation illustrates why you need a trusted jeweler when selecting a diamond. Buying a diamond is not like buying a toaster, every diamond is different, having its own unique set of characteristics. Diamonds are expensive, it is too important a decision to make with generic advice from a website. The customer probably saved a few hundred dollars by going with the website's diamond, I'm confident they now believe they made a big mistake.
When I sell a diamond I am selling more than a brilliant gem, I am selling my reputation. Never would I sell a diamond that I didn't think was stunning, that I wouldn't give to my own wife. A Spiegel and Son diamond is hand selected for beauty, quality, and value. That is why you need a trusted jeweler, that is why you need Spiegel and Son.