Extending its losses for the third straight day, gold dropped 220 rupees, to 31,710 rupees per ten grams at Delhi's bullion market, today, on sustained selling by stockists, amid sluggish demand, and a weak global trend. But silver gained 510 rupees, to 50,100 rupees per kilo, on increased offtake by industrial units and coin-makers. Silver coins spurted 1,000 rupees, to 88,000 rupees for buying 100 pieces, on an upsurge in demand.