Tough as the robust gorilla but flexible enough to suit any screen size and designs, that is the next screen material geared for the upcoming iPhone 6 and iPhone 5S, courtesy of device screen maker Corning.

In a recent campaign that obviously debunks sapphire's alleged superiority over the tried and tested Corning Gorilla, deployed both in iOS and Android devices, the company stressed that it has already invented a glass cover that "was about half the weight, used 99 per cent less energy to make, provided brighter displays and cost less than a tenth of sapphire."

Jeffrey Evenson, senior vice president for Corning, pointed to the Corning Gorilla Glass 3 as the best there is, to date, in smartphone cover.

"Gorilla Glass requires about three times more force to break than sapphire after both materials have received similar wear and tear," Mr Evenson told MacRumors in an interview.

The company also emphasised that at the moment, sapphire's production cost and environmental impact are two grave concerns yet to be addressed.

The continued use of the material to Apple's iPhone 6 and iPhone 5S fully conforms with the upcoming design plans of the tech giant, Corning said, especially in iPhone 6's case, which is rumoured to intro the use of wrap-around and bendable phone screen.

Gorilla Glass is a gadget designer's delight, giving more room to come about with revolutionary designs, such as the continuous front and back screen suggested by a recently published Apple patent.

Corning insists that Gorilla Glass is thin enough to accommodate the rumoured curved screen displays not only of the iPhone 6 but also of other mobile phones.

Corning's clarification campaign came out as reports earlier emerged that Apple is mulling a shift to sapphire following the material's deployment with the iPhone 5 last year to protect the phone's camera lens.

Reports emerged last week that sapphire could play a bigger role in future iPhone models as it offers more resistance against dents and scratches. Leaked information hinted that Apple is ditching the physical Home button in the iPhone 5S and its place will be a capacitive key, protected by a sapphire coating.

Analysts believe that the iPhone 5S is geared for a September 2013 debut while the iPhone 6 is pegged for a June 2014 release date. Both handsets will come with faster processors and a leaner iOS 7 profile.