I don't know how to grade diamonds or gemstones. It has been tested positive for diamonds and gold The stones look to be very clean and beautiful color but I do not know how to grade it. Sorry wish I could be more help. The item "VINTAGE ESTATE 14K GOLD DIAMOND PENDANT FLOWER SIGNED NJ CHINESE PIN BROOCH" is in sale since Wednesday, March 21, 2018. This item is in the category "Jewelry & Watches\Fine Jewelry\Fine Pins & Brooches\Diamonds & Gemstones".The seller is "4744366" and is located in Andover, Massachusetts. This item can be shipped worldwide.