A new diamond grading document has been introduced by the American Gem Society (AGS) and the American Gem Society Laboratories LLC.%%The new document is called the 'Diamond Quality Certificate' or DQC.%%DQC is available exclusively to AGS retail members and is a guarantee of authenticity and performance by the jeweler.%%The DQC cannot be issued for diamonds sold via the Internet and must be signed by an American Gem Society titleholder in the presence of the consumer.%%The American Gem Society Laboratories will grade diamonds qualifying for the DQC.