Gold rallied on Friday, but was still set for a 1.5 percent decline this week as investors watched the progress of a crucial European Union summit with dwindling confidence that it would resolve the two-year-old debt crisis. Spot gold was last up 0.7 percent on the day at $1,719.10 an ounce by 1122 GMT, on course for a fall of 1.5 percent on the week, its third week of losses in the past four.