A new, questionable rumor from Korea claims that Apple's next-generation iPhone will replace its glass back with the super-durable Liquidmetal alloy.

The claim was published on Wednesday by Korea IT News, which said Apple's sixth-generation iPhone will be made of zirconium, titanium, nickel, copper "and so forth." It also said it will have a "surface smooth like liquid."

Though the report includes references to a general "liquid metal," the proper noun Liquidmetal refers to an amorphous metal that Apple purchased the exclusive rights to use in 2010. The company behind the material, Liquidmetal Technologies, revealed in March that it was paid $20 million by Apple in that deal.

Casting some doubt on Wednesday's report out of Korea, it goes on to say that the new iPhone is expected to debut at Apple's Worldwide Developers Conference in San Francisco in June. Last year, Apple opted to hold off on unveiling the iPhone 4S until well after WWDC, and launched its fifth-generation handset in October.

This year, most rumors have suggested that Apple plans to hold to a similar timeframe for the launch of a sixth-generation iPhone. It has been rumored that Apple will unveil its next handset in the months of September or October.

While the WWDC launch reported by Korea IT News is questionable, claims of a metal back for the next iPhone are not new. As far back as last year, there were indications that Apple was working on an all-new iPhone design with a metal back akin to the iPad.

As for the potential use of Liquidmetal, the company that owns the material announced in March that it had begun shipping commercial parts to "several" unnamed customers. Apple's Liquidmetal gives it the right to exclusively use the material in electronic products, though it is free to be used in other industries like defense contractors, sports equipment manufacturers and medical suppliers.