Established in 1975, the IGI (International Gemological Institute) operates globally, meticulously examining colored stones, jewelry, and lab grown diamonds for authenticity. They provide a lab grown diamond report that vendors can present alongside their diamonds, ensuring buyers can verify the diamond's authenticity. Most certified lab grown jewelry experts offer this certification from the International Gemological Institute. Checking for this certificate when buying diamonds is crucial to ensure you're getting the best value and avoiding uncertified diamonds.

Established in 1931, the GIA (Gemological Institute of America) offers a rigorous certification program, including a research-based curriculum taught by top diamond experts. Renowned for its strict and consistent grading system, GIA serves as the industry benchmark, having introduced the 4Cs. The GIA's scale assesses color, size, position, nature, carat, clarity, and cut, with 11 clarity grades ranging from flawless to included, where the latter may affect a diamond's brilliance and transparency.

In the United States, diamond certificates are issued by three main laboratories: the GIA (Gemological Institute of America), the AGS (American Gem Society), and the European Gemological Laboratory - USA (EGL or EGL USA). AGS certificates are often preferred over EGL certificates due to their stricter grading standards. Consumers favor GIA and AGS for their credibility. Each lab employs different grading systems, with AGS using a 0 to 10 scale and a colorimeter for precise assessment, aided by master diamond sets for comparison during grading.