Gold tumbled 225 rupees, to 30,820 rupees per ten grams at Delhi's bullion market today, on selling by stockists, triggered by a weak global trend. Silver dropped 230 rupees, to 58,750 per kilo.Oversaeas, gold fell 0.2 percent, to 1,660 dollars an ounce. Silver lost 0.2 per cent to 31.40 dollas an ounce.