Gold, heading for its longest run of monthly losses in almost 13 years, gained on Thursday as a weaker dollar bolstered demand for commodities. It rose 0.2 per cent to $1,566 an ounce, placing itself 0.1 per cent higher this year. Silver gained 0.6 per cent to $28.06 an ounce, still set for a third monthly loss, also the worst run since 2008.