Gold prices sank further on Friday, capping their worst week in 15 years as investors fretted about the economic implications of the U.S.-Iran War. Futures tied to the yellow metal dropped 0.7% to $4,574.90 an ounce, pulling back from gains earlier in the morning. The metal plunged 9.6% this week, its biggest weekly loss since since September of 2011. Gold is on track for its worst month since Oct...