Why is it important that my diamond certificate come from an independent diamond grading laboratory?

If you were buying a house would you accept an inspection from the owner? Of course you wouldn’t, you would insist that the inspection be done by an expert with no financial interest in the transaction. This situation is the same when buying diamonds. Be careful of diamond reports produced in-house by diamond merchants or retailers, as the report may be inaccurate and overstate the actual grading of the diamond.