Apple could soon be a major buyer of gold, according to estimates of how much of the precious metal will be required to produce the 18-carat version of the forthcoming Apple Watch.

Bullion dealer GoldCore has estimated that each gold edition of the Apple Watch could contain two ounces of gold, suggesting that Apple could use 746 tonnes of gold per year, or one-third of the total annual global mine supply.

The figure is based on estimates that Apple has ordered between five and six million units of smartwatches from its manufacturers, CNBC reported.

By comparison, some 800 to 1,000 tonnes of gold finds its way into India every year, the leading consumer of the yellow metal.

Cost

GoldCore's research director Mark O'Byrne said that if each Apple Watch Edition required two ounces of gold, which was likely if the watch has a gold bracelet in place of a strap, it will cost Apple roughly $2,400 per phone to produce.

But despite the hype, O'Byrne said Apple's reported expectation of shipping one million units of the Edition model will be "a tall order".

The Apple Watch will be unveiled on 9 March in San Francisco and go on sale in April.

The gold version, called Apple Watch Edition, is expected to retail at between $4,000 and $10,000. The watch case for the Edition model is crafted from 18-carat gold that is twice as hard as standard gold, according to Apple.

O'Byrne said in a note: "Around one-third of the order will be made up of the mid-range watch, leaving an estimated one-sixth of the order to be comprised of the gold edition."

"In the end it will probably come down to the price. Even at the lower-end [selling price] estimate of $4,000, it's hard to imagine Apple shifting one million units each month.

"However, Apple's ability to generate a buzz or hype, depending on your perspective, cannot be under-estimated."