Falling for the third straight day, gold dropped 255 rupees, to 26,565 rupees per ten grams at Delhi's bullion market on Thursday, on sustained selling by stockists, in tandem with a weak trend overseas.Silver plunged 1,100 rupees, to 52,200 rupees per kilo.Overseas, gold shed 1.9 per cent, to 1,610 dollars an ounce.