Gold prices dropped by ₹600 to ₹1.64 lakh per 10 grams in the national capital on Friday as tentative progress in US-Iran negotiations reduced precious metals buying. Silver prices remained flat at ₹2,71,000 per kilogram in the bullion market. In international markets, spot gold fell marginally lower to $4,522.32 per ounce, while silver slipped 1% to $75.87 per ounce.