Gold rose 65 rupees, to 30,990 rupees per ten grams at Delhi's bullion market, today, on emergence of buying at lower levels by retailers, amid a firm global trend. But silver dropped 600 rupees, to 57,000 rupees per kilo, on lack of necessary buying support from industrial units and coin makers.Overseas, gold rose 0.5 per cent, to 1,664 dollars an ounce. Silver gained 0.8 per cent, to 30.25 dollars an ounce.