African Producers: Use 4Cs Only for Natural Stones

(IDEX Online) - African diamond producers are calling for lab growns to be measured in grams rather than carats, and for 4Cs grading to be reserved only for natural stones.

The African Diamond Producers Association (ADPA) announced the move on Monday (25 May) after a summit in Freetown, Sierra Leone.

The ADPA, based in Luanda, Angola, represents 15 diamond-producing countries, and 70% of global output.

It has no powers of enforcement, but is lobbying international trade bodies, governments, and grading labs to adopt its approved standards.

Several countries, including France, India and Belgium, require lab-grown diamonds to be clearly distinguished from natural stones, through mandatory qualifiers or separate weight-labeling rules.

In addition, Belgium has, since a royal decree of 2023, required lab growns to be labelled in grams rather than carats.

The GIA has, since last October, dropped 4Cs grading for lab growns, describing them only as premium or standard, but other major labs haven't followed suit.

The ADPA said it was calling for "the exclusive use of the internationally recognized 4Cs grading system and carat weight measurements solely for natural diamonds".

It also said synthetic stones should be measured in grams/kilograms and explicitly identified as 'synthetic' as the sole descriptor in international trade and marketing.

"We are at a tipping point," Tanzania's deputy minister of mines, Steven Kiruswa, told delegates at the summit.

"The proliferation of lab-made diamonds is eroding the value, credibility and livelihoods tied to natural diamonds. If we do not act together, we risk undermining one of Africa's most strategic natural resources."