Certified and non-certified diamonds?

A certified diamond means any diamond which has been measured and quantified. The measurements and quality of the diamonds are printed on a paper. The certificate is given to the buyer at the time of purchase. A non certified diamonds means that there is no assurance of measurement and quality. Certified diamonds are more expensive than non-certified because not only do they look pretty, but they have the papers to prove that they are that pretty and valuable, and they usually have a serial number that gets stamped on the piece of jewelry and on the certification paper.

If you're interested in the investment value, or if you're spending more than a hundred or two dollars, you probably want to buy certified, for the guarantee of the stone's value. If you really don't care about quality and just want a pretty diamond, or if you have a habit of losing things like I do, uncertified probably meets your needs.

The qualities can be identified on an uncertified diamond; lack of certification simply means that the qualities haven't specifically been measured and recorded. They are certified by independent groups, not by the jeweler who's selling it to you.