Gold fell to its lowest in 2-1/2 months on Tuesday, breaking through key support at its August lows as stock markets rose and the dollar hit a one-year high against the euro ahead of a European Central Bank meeting this week. The metal has been underpinned by worries over the stand-off between Russia and the West over Ukraine and persistent unrest in the Middle East, but strength in stocks and the dollar, plus weak physical demand from China and India, has offset that.