September 23, 20 by John Jeffay
(IDEX Online) – A new set of standards for grading polished diamonds has been drawn up and published by the ISO.
The Geneva-based organization certifies the quality of a vast range of 23,000 products, services and systems across the world.
It has now issued a ground-breaking 55-page document for the diamond industry specifying the terminology, classification and methods are used for grading and describing any single unmounted polished diamond over 0.25 carat.
The document – ISO 24016 – updates worldwide standards for the 4Cs from a 2015 publication to prevent discrepancies between labs.
“Some diamond grading reports may be issued based on different standards by different laboratories, potentially leading to different results for the same individual diamond,” says the introduction.
“This situation damages the reputation of the whole diamond trade. Hence, the need for a unique ISO standard for grading polished diamonds.”