Gold futures on the COMEX division of the New York Mercantile Exchange rallied Thursday, supported by a strong Chinese export data and a weakened U.S. dollar. The most active gold contract for February delivery rose 22.5 dollars, or 1.36 percent, to settle at 1,678 dollars per ounce. Trade data released overnight suggests demand in China remains strong, which is seen as positive for gold prices, market analysts say, and the European Central Bank\'s unanimous vote to keep interest rates on hold was also seen as positive for gold thanks to the rallying euro. China\'s December export jumped 14.1 percent from a year earlier, up from a 2.9 percent gain in November, while import was up 6 percent from zero growth in the previous month, according to data released by the General Administration of Customs on Thursday. Gold prices were helped by a drop in the U.S. dollar, which makes greenback-denominated commodities cheaper for other currency holders. The ICE dollar index fell to 79.709 from 80.514 in late North American trading on Wednesday. Silver for March delivery rose 66.9 cents, or 2.21 percent, to close at 30.918 dollars per ounce.