Gold prices fell on Tuesday, retreating from near a four-week high, as a modest rise in the dollar weighed on the metal, although uncertainty over the U.S.-China trade agreement kept investors cautious and limited the bullion's decline. Sven Hoppe | Picture Alliance | Getty Images Central banks are increasingly looking to bolster their gold reserves. And they are turning to mines in their backyard to source the yellow metal. Besides being cheaper, securing gold directly from mines helps support local indust ...