ACA Gemological Laboratory

ACA Gemological Laboratory

Advancing the Science of Diamond Grading

Welcome to ACA Gemological Laboratory, where scientific research, objective measurement, and practical gemological experience combine to advance the understanding of diamonds and diamond grading.

Founded by Michael D. Cowing, M.Sc., FGA, ACA Gemological Laboratory is dedicated to improving the accuracy, consistency, and understanding of diamond evaluation through original research and education.

What's New

Objective Diamond Clarity Grading

ACA Gemological Laboratory is proud to announce the publication of Objective Diamond Clarity Grading, a groundbreaking work introducing a science-based system for evaluating diamond clarity using objective, measurable criteria.

Now available in hardcover and paperback editions.

Visit the Objective Diamond Clarity Grading page for a complete description of the book, sample pages, and ordering information.


Diamond Research

Explore original articles covering:

  • The Ideal Round Brilliant Cut
  • Diamond Light Performance
  • Brilliance, Fire, and Scintillation
  • Diamond Color and Clarity
  • Diamond Optics
  • New Perspectives on the Four Cs
  • Advanced Gemological Research

Whether you are a gemologist, appraiser, jeweler, student, or diamond enthusiast, these articles provide a deeper understanding of diamonds beyond conventional teaching.

Questions, comments, and professional inquiries are always welcome.