ISO Establishes Diamond Grading Guidelines

Grading
28/09/2020 15:23

For the first time, the International Standards Organization (ISO) has established guidelines on diamond grading, specifying terminology, classification and methods for grading natural diamonds above 0.25ct in order to create more consistency between grading labs. The guidelines are based on CIBJO's Blue Book and are the result of a request made by the Swiss Association of Standardization. Recently, the ISO guide to the use of terminology for natural and synthetic diamonds and simulants, which defines diamonds as a natural mineral, was reconfirmed in a review.