A 500 yen coin made with a new mix of metals will debut in August to combat a vending machine con in which altered 500-won South Korean coins are redeemed for the more valuable domestic coin, the Finance Ministry announced Friday. It will be Japan's first reminting of a coin as an anti-counterfeiting measure since the end of World War II. The reminting will follow the July issuance of a 2,000 yen bill to mark the year 2000 and the country's hosting of the Group of Eight summit in Okinawa. The material used in the 500 yen coin will be changed from white bronze to nickel chalcopyrite mixed with zinc. The new material will change the coin's conductivity so that vending machines can reject altered substitutes, the ministry said. Other features will include a latent image on the surface and a milled edge, though vending machines will not recognize these features, the ministry said. The size and basic design will remain unchanged. The ministry will stop producing the current 500 yen coin by the end of this month. "It may give people a little inconvenience," said Yoshinori Ono, senior state secretary for finance. But some vending machines do not accept 500 yen even now to avoid counterfeits, he added. The coin, with a circulation of 2.5 billion as of October, will still be in use even after its successor begins circulating. The ministry will ask that more than 5 million vending machines across the country be adjusted -- at an estimated cost of 20,000 yen per machine -- to no longer accept the current 500 yen coin. Between January and October police found 657,000 altered coins, most of which were 500-won coins.
