IGI Labs Win ISO Certificate for Grading Lab Growns April 06, 21 by John Jeffay (IDEX Online) - The IGI labs have become the first in the world to be accredited by the ISO for the reliability of their lab-grown grading. The New York-based International Gemological Institute already had certification for its work with mined diamonds. The ISO - International Organization for Standardization - has now tested its efficiency a nd accuracy in grading lab growns and awarded it the ISO/IEC 17025 certification. IGI, which has 18 labs worldwide, says it certifies the vast majority of lab-grown diamonds in the United States, India and China and has been a pioneer in the field since 2005.