Platinum jumped to a record high of $ 1,591.50 an ounce and was last quoted at $ 1,586 / 1,591 , against $ 1,551.50 / 1,556.50 in New York , after Lonmin Plc ( LMI.L : Quote , Profile , Research ) , the world 's No.3 platinum producer , cut its sales outlook for the year .