The 4c of Diamonds 

When talking about diamonds, one of the first things that is brought into a conversation is, …do you know of the 4c’s …. ? Almost every internet presentation having something to do with diamonds feels the need to decorate them selves with this all so important knowledge. Unfortunately one sees very seldom a reference to the creators of this 4c grading system.



Diamonds and gemstones of similar appearance can have important differences in value.

IGI's supreme position in the gemological world is no coincidence. It is the result of continuous research, support and synergy with professionals and consumers alike.


EGL USA and its gemologists
deliver state-of-the-art analysis and unparalleled customer support.

For over three decades, EGL USA has provided cutting-edge gemological research, testing, and laboratory analysis. This ongoing scientific work reflects the lab’s core commitment


My HRD Antwerp is a secure, 24/7 online service that provides global access to the HRD Antwerp certificate archive and transit results.

The Diamond Lab of HRD Antwerp was founded in 1976 to meet the growing demand for reliable diamond certificates or grading reports.