Given that the established labs don''t certify CE diamonds -- is there any basic guideline with respect to pricing vs. a discount for a natural untreated stone. Looking at CE earrings -- 6 ct TW ... H or I with good cut & brilliance, but probably I1 or I2 before CE treatment. If natural -- I''d expect the stones to range at least $2800 per ct per the Rap Report. If so, what is the haircut for the CE treatment -- 20%, 30%, 50%?