Ahead of the deadline for Iran to reopen the Strait of Hormuz, investors remained cautious, with gold prices rising on Tuesday. Spot gold last increased by USD56, or 1.2%, to USD4,706 per ounce.Gold futures for June delivery were flat at USD4,684.7 per ounce.Silver futures for May delivery fell 1.2% to USD71.987 per ounce.Copper...