By RHIANNON HOYLE And CLEMENTINE WALLOP SYDNEY—Sales of gold and silver coins are surging despite the sudden plunge in precious metals, benefiting mints around the world and driving the cost of the collector items to well above the value of the metal they are made of. Coins account for about a fifth of all gold purchases for investment and are traditionally favored by retail investors because they are far cheaper than the larger bars bigger investors buy. While traders dumped gold futures earlier this week on signs global inflation is easing and the world economy is slowing, the slide in coin prices has been cushioned by high demand from gold enthusiasts who say it will hold its value over the long term. Related Video Mark Hulbert advises investors not to expect gold prices to pop back anytime soon. He points out gold's fair-market value may be no more than $800 an ounce. The premium on gold coins has risen to about 5% more than the spot price of the metal, and compares with 3% at the start of the year, traders say. For silver, the premium has risen to as much as 18% more than the silver price, and compares to about 15% at the start of the year. Comparisons aren't precise as the coins generally contain small amounts of other metals to strengthen them, and there is typically a small premium because of manufacturing costs. "The premium for coins is getting higher and higher," Singapore-based Silver Bullion Pte. Ltd. Director Gregor Gregersen said. "They're harder to get hold of and, as people see that, some of them are going into a panic." Gold shops from Tokyo to Dubai have witnessed frantic buying of the coins, alongside other items such as gold wedding bracelets. The surge has been triggered by cheaper prices with gold falling 18% since the start of this year and 6.8% since late last week to around $1,380 a troy ounce. Australia's biggest gold refiner, The Perth Mint, says demand for coins and bars has jumped in the past two days, after an already strong start to 2013. Before this week's gold rout, the mint's first-quarter gold coin sales were already up nearly 50% compared with last year. "There has been huge retail demand," said Perth Mint spokeswoman Makeila Ellis. "The phones have been ringing off the hook." Demand for classic American Eagles—the most popular gold coin in the U.S.—has jumped by more than 65% between Friday and Tuesday as gold prices plummeted, according to the U.S. Mint. So far this month, 83,500 ounces of gold American Eagles have been sold, compared with 20,000 ounces in the whole of April 2012. Related Reading The U.S. is the second-biggest producer of gold coins, behind Turkey. A representative for the Turkish State Mint didn't respond to requests for comment. Canada's government-owned mint said it too had recorded high coin interest. "Demand continues to be very strong for Gold Maple Leaf and Silver Maple Leaf coins through the recent move in the market," said Chris Carkner, managing director of sales for the mint's bullion, refinery and exchange-traded products. The demand is leading to supply shortages with traders in Singapore saying they've been told to wait as long as seven weeks for fresh deliveries of the U.S. and Canadian minted coins. In India, gold imports are likely to rise to around 900 metric tons this year to meet rising demand that is coinciding with the peak marriage season, industry executives said. That is above the 860 tons imported last year. "It's been nearly two years since people have been getting such low prices, so those waiting for more favorable buying conditions are now coming forward," said Riddisiddhi Bullions Managing Director Prithviraj Kothari.