Shopping for certified diamonds allows you to make an informed choice about your diamond selections and to comparison shop among various diamond merchants.
You can compare one diamond with a particular weight and quality with other diamonds of similar weight and quality to determine which diamond is the better value -- or which merchant has the best prices.
[NOTE: If a jewelry store offers to sell you a loose diamond without a certificate, 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 gemologist or even other jewelers may disagree with the salesperson's assessment.]
