Polished diamonds are certified in compliance with the specification TU 117-4.2099-2002. Only loose polished diamonds manufactured from natural rough diamonds are subject to certification. Diamond certificates contain the information on the basic parameters of polished diamonds,such as cut grade, carat weight,color grade, clarity grade and fluorescence.
Besides, basic dimensions of polished diamonds are to be determined. They are:
- minimum diameter
- maximum diameter
- length and width (for fancy shape polished diamonds)
- total depth
- crown angle and pavilion depth
- girdle thickness
- symmetry and polish
Certificates also contain detailed designs of polished diamonds with all the internal and external defects. Certified polished diamonds are placed in clearplastic sealed package. Such package is tamper resistant and will be disrupted as soon as the sealing is opened. The mark of conformity of the Cut Gemstones Certification System is printed on the seal.There is a label with the name of the Centre, mark of conformity of the System, basic parameters of polished diamonds and certificate number inside the package. Certificates are printed on blue A4 stamped paper with dark geometrical watermarks and other additional security features. Filled in certificatesare laminated.The packet shows that the diamond has been graded by a certification centre,and the information in it matches the gemstone.