State Inspection is the National Center for Quality Supervision and Inspection of Jewelry and Jade, and GIA is the Gemological Institute of the United States.
In China, the most authoritative appraisal institution is the appraisal certificate issued by the State Inspection Bureau, and the GIA certificate is universal and the most authoritative. There is a difference between the two. GIA must identify the bare stone after the national inspection and re-identification. Let's analyze the difference between the appraisal certificates (simply analyze it, and you can find me at Baidu hi if you want to know more).
If the national inspection identifies 4c, colors are classified into major categories, such as D-E F-G H I-J and GIA are classified into subcategories. The same is true for the clarity of D E F G, and the national inspection scores VVS, GIA scores VVS, vvs 1 vvs2, etc. The national inspection division is very good and more detailed than General GIA.
Finally, tell me about your situation. If you want to buy brand diamonds, it is enough to choose the national inspection certificate. The reason is that the GIA certificate is more expensive and unnecessary. Secondly, just now I also said that GIA is a bare stone test, and it may not be the original factory after the test, but the national inspection has decided to test it together.
If you want to buy rough diamonds, you must look for GIA certificate, because the appraisal is more detailed, and the waist edge and GIA number of diamonds can preserve the value, as you just said. As long as the diamond really has nothing to do with the certificate, if you buy a finished diamond, you don't need to keep the value. If you buy the original stone, it is ok.
I can only give you a simple answer. If you don't understand, you can leave me a message on Baidu hi.