WFDB President Ernie Blom

"Each of our member bourses, of course, has full decision-making power regarding which types of diamonds can be bought and sold within their premises as long as the decisions are made in line with the WFDB's regulations," Blom commented.

"I would reiterate that we are not opposed to trading in synthetic/ laboratory-created diamonds and accept that there could be a market for them. We only insist that such stones are fully disclosed so that the trade and consumers know exactly what they are being offered. This is critical in ensuring consumer confidence.

"As the Bharat Diamond Bourse said in its media statement following the vote in favor of banning synthetic/ laboratory-grown diamonds, its decision aims to ensure the growth of the natural diamond trade, strengthen consumer confidence and reassure faith and trust in diamonds. These are aims that the WFDB fully supports."

The BDB statement said that at its 31st Annual General Meeting held on 28 September 2015, "a resolution was proposed to declare that no person / organisation shall promote or trade or carry synthetic diamonds / lab grown diamonds / man-made diamonds within the premises of Bharat Diamond Bourse and only 'Natural Diamonds' will be traded in the premises of the Bharat Diamond Bourse. The resolution was placed before members at the Annual General Meeting and was approved by an overwhelming majority of the members and was passed in its entirety."

Last year, the Israel Diamond Exchange announced it was banning trading in synthetic diamonds on its trading floor.