World Jewellery Confederation welcomes new ISO diamond grading standard

23rd September 2020 By: Marleny Arnoldi - Deputy Editor Online

World Jewellery Confederation welcomes new ISO diamond grading standard

The World Jewellery Confederation (Cibjo) has welcomed the new publication by nongovernmental body International Standards Organisation (ISO) of the internationally recognised diamond grading standard and says it is a historic moment for the global diamond industry.

The confederation explains that the standard is the first-ever that has been approved by the body that specifies the terminology, classification and the methods to be used for the grading and description of single unmounted polished diamonds.

“For the first time, a strictly defined diamond grading system has been ratified by the world’s leading standards body, formally recognising principles and terminology that, to date, had not been approved by any impartial and international authority.

“The ISO 24016 essentially parallels the Cibjo Diamond Blue Book, meaning that the confederation’s widely-accepted standard is effectively validated by ISO,” notes Cibjo president Gaetano Cavalieri.

The standard applies to natural, unmounted, polished diamonds of more than 0.25 ct and aims to set rules for determining – with maximum prevision and accuracy – the mass, colour, clarity and cut of individual polished diamonds.

There has been a need for a unique ISO standard for grading polished diamonds, since some diamond grading reports are issued based on different standards by different laboratories, leading to different results for the same individual diamond.

These mixed results damage the reputation of the whole diamond trade, says Cibjo.

The standard does not apply to fancy coloured diamonds, synthetic diamonds, assembled stones or diamonds treated by methods other than laser drilling.

ISO has another standard for defining specific nomenclature for natural diamonds, synthetic diamonds and diamond simulants.

“There is no doubt that these two international ISO standards, together with the Cibjo Blue Diamond Book, will help boost consumer confidence in the industry,” says Cibjo diamond commission president Udi Sheintal, adding that the timing is relevant now when clear distinctions need to be made between lab-grown diamonds and natural diamonds.