New Delhi: Gold prices retreated by Rs 2,640 to Rs 1.47 lakh per 10 grams in the national capital on Tuesday, and silver dropped Rs 5,200 per kg, tracking weak global trends and a firm rupee. Silver also witnessed selling and tumbled Rs 5,200 to Rs 2,24,800 per kilogram (inclusive of all taxes). The white metal had settled at Rs 2,30,000 per kg in the previous session. Traders said a stronger rupee reduced the landed cost of imported bullion in the domestic market, while weak global trends and caution ahead of the US Federal Reserve's policy decision kept investors' sentiment subdued. "Gold edged lower on Tuesday, retreating from the previous session's gains as investors turned cautious ahead of the US Federal Reserve's policy decision," said Saumil Gandhi, Senior Analyst - Commodities at HDFC Securities.