Global gold prices tumbled on Friday, losing nearly 2 percent, as a surging U.S. dollar and renewed fears of interest rate hikes weakened the metal’s safe-haven appeal. Spot gold dropped 1.8 percent to $4,566.26 per ounce by late morning trading, reversing earlier gains, while U.S. gold futures for April delivery declined 0.8 percent to $4,570.20.…