Your purchase of a diamond engagement ring and jewelry shows you a diamond with a diamond certificate, (DC) and the following jewelry shows you a diamond with a diamond grading report. (DGR) You may have been shown a DGR in both cases, DGRs are often called diamond certificates.
Diamond Certificate: (DC)
A diamond certificate is a document prepared by gemological laboratories to identify a stone. The certificate usually has the type of stone, the dimension of the stone, the weight, and sometimes the color when needed. It will also include any treatment the stone has had and sometimes the origin of the stone.
Diamond Grading Report: (DGR)
A diamond grading report is a document from a laboratory to classify the color, clarity, cut, and carat weight of diamonds or what is known as (4c). These reports are often called Diamond Certificates, the correct term is (Diamond Grade Report).
You must know the difference between the two; Of course, the (DGR) is a better document to go with when shopping for a diamond. This report has all the items you would need to determine the value of the stones you plan to purchase. Many stores will create their own, in some cases this would be fine if it is a store that has a GIA certified diamond grader who would be grading the diamond and making a certificate for your stone. If you are shown a document in a diamond that has the (4c) included in the document, but it is called (DC), it is not, it will be the (DGR).
When you are ready to purchase your diamond, be sure to view all the documentation on the stone you are purchasing. If the stone does not have a (DGR), send the stone to one of the many laboratories that do a diamond report. There are several very good labs and your jewelry should be able to take care of this for you.