Links
Gemmological Institute of America
Diamond Grading Certification
http://www.gia.edu/
HRD Antwerp Institute of Gemmology
Diamond Grading Certification
http://www.hrdantwerp.be/en/home.aspx
IGI International Gemmological Institute
Diamond Grading Certification
http://www.igiworldwide.com/
EDL European Gemmological Laboratory
Diamond Grading Certification
http://www.eglinternational.org/serv_certificates.htm
EDR European Diamond Report
Diamond Grading Certification
http://diamond-reports.com/
BGI British Gemmological Institute
Diamond Grading Certification
http://www.bgiuk.com/FAQsPage.htm
AnchorCert Gemmological Laboratory
Diamond Grading Certification
http://www.anchorcert.co.uk/