Having a certified diamond typically gives you a respected, independent third party opinion to the quality of the diamond you are purchasing.
Make sure the certificate provided with your diamond comes from an international, respected, independent diamond grading laboratory. It is also reassuring to seek the advice of a well informed, trained professional, to ensure you are confident about the quality of your certified diamond. All diamonds sold by Diamond Guild Australia members are certified. Your member can give you any advice you require about certificates.
An uncertified diamond is not necessarily a bad diamond. However, its stated quality is based only on the word of the seller not on an independent grading process. Having a diamond certificate helps you verify details and information in the event of an insurance or replacement issue.