Date on the Certificate The date on a certificate is much more important than you might think. The date is important because it tells you whether the stone might have been worn and damaged since the diamond was evaluated. If a certificate is 2 years old, for example, it would be possible for the diamond to have been graded, sold, set, worn for a while, damaged a little during normal wear and tear, taken out of the setting, and put back on display at a jeweler. So we recommend you should at least ask when a certificate is older than 2 years. Diamonds are not invincible. They can be cracked, chipped, or abraided around the edge (the girdle). This alone will make the diamond less valuable -- and if the damage is large enough, less attractive as well. And if you recut the stone to remove the damage, the lost weight will still decrease the value of the diamond accordingly. Therefore, we recommend asking about any diamond with a certificate that is more than a year old. Just ask to make sure it has not been worn since the certificate was written. You can also examine the stone under a scope and look for abrasion around the girdle, which is the most common damage during normal wear and tear. Back to: How to Read a Certificate