Platinum Guild International USA (PGI) has highlighted the importance of the purity of platinum and has called on the industry to take part in an upcoming event discussing a new lower karat platinum alloy.

The organisation wants all platinum jewellery to be of a certain standard and is against the new alloy introduced by Karat Platinum.

Huw Daniel, PGI-USA's president, told JCK: "We want to get across that we are standing by our position of platinum jewellery being 90 per cent or higher [platinum content in an alloy] and alloyed only with platinum-group metals [in order to be marked platinum]."

Karat Platinum, which put in a request for the new alloy to the Federal Trade Commission (FTC), hopes to mark products as "585 Plat. 0 PGM" and argued it wants to be "as transparent as possible" and allow everyone to "fully understand" the alloy.

The FTC has so far stated that the proposed mark is "neither prohibited or allowed" and is now calling for industry comment.

However Karat Platinum has claimed it will change the mark to read "585 plat, .415 CO/CU" to show that the alloy contains platinum, copper and cobalt, rather than what it doesn't.

It is thought a number of companies will promote jewellery made from the .585 platinum at this June's JCK Las Vegas show.

PGI USA has now sent a letter to 400 manufacturers and retailers to encourage them to keep platinum's purity levels, since concerns have been raised the new alloy could undermine platinum's current high position for purity and investment value.