Gold gained 50 rupees, to 31,250 rupees per ten grams at Delhi's bullion market, on Tuesday, on increased buying by jewelers, even as the precious metal weakened overseas. But silver declined 450 rupees, to 45,000 rupees per kilo, on reduced offtake by industrial units and coin makers. Silver coins remained unchanged, at 77,000 rupees for buying 100 pieces. Overseas, gold lost 0.4 percent, to 1,307 dollars an ounce, as a strengthening dollar reduced demand for the precious metal as a safe-haven.