The Istanbul Gold Exchange Index gained 0.67 percent in value Monday, as gold was traded at 88,100 Turkish lira per kilogram.The trading volume in the gold market was 18.3 million Turkish Lira in 15 transactions and $24.05 million in 13 transactions.The trading volume in the silver market was 2.3 million Turkish Lira in two transactions and $656,920.28 in two transactions.