Gold prices jumped 250 rupees, to 30,900 rupees per ten grams at Delhi's bullion market, today, on increased buying by jewellers. Silver spurted 1,550 rupees, to 47,750 rupees per kilo, on increased offtake by industrial units and coin makers. Silver coins surged 2,000 rupees, to 76,000 rupees for buying 100 pieces.