Gold plummeted 505 rupees, to an over 10-month low of 29,470 rupees per ten grams at Delhi's bullion market, today, on heavy selling by stockists, driven by a steep fall in the overseas markets. Silver dropped 875 rupees, to 52,275 rupees per kilo, on restricted buying by industrial units and coin-makers. Silver coins plunged 2,000 rupees, to 79,000 rupees for buying 100 pieces.