Gemological Science International (GSI)

The diamond grading industry is populated by gemological laboratories that are virtually indistinguishable. In this “alphabet soup” of grading labs, diamonds are graded by hand and eye – an ultimately subjective assessment. While this continues to be standard practice for all laboratories, GSI has enhanced this process by using advanced technology and intelligent software.

We at Gemological Science International (GSI) have a vision: to create a modern, state-of-the-art diamond grading lab that takes advantage of the latest breakthroughs in diamond grading. To do this, we reengineered the diamond grading process and founded it on foolproof cutting-edge technology and automation. The result is diamonds that are graded to the highest standards.

GSI grading reports are an objective and accurate analysis of a diamond’s 4Cs and more. They are the culmination of decades of research and the industry expertise of hundreds of our dedicated professionals around the world.

GSI grading reports can be accessed any time from our secure database – a key benefit should you ever misplace it or its authenticity is questioned. Similarly, consumers often use term “GSI certificate” to describe GSI grading reports. Don’t be confused by the terminology. The terms are interchangeable. And no matter what you call it, GSI grading reports stand for innovation, integrity, and professionalism.

Above all, our efforts have resulted in grading certificates that gives your peace of mind when making that most important purchase.

For assistance please email to or call GSI office in your country.
You can find the phone information by following the link

       Enter Report Number