Gold futures rallied Thursday to top $1,800 an ounce, with prices marking their highest settlement since February. Prices got a boost from weakness in the U.S. dollar, as well as a decline in 10-year Treasury note yields. Getting above the key level of $1,800 is a "positive as it keeps the series of higher highs and higher lows that began in April in place, and the near-term trend to the upside," said Dan Russo, portfolio manager at Potomac Fund Management. June gold /zigman2/quotes/210036734/delayed GCM21 -0.36% rose $31.40, or 1.8%, to settle at $1,815.70 an ounce. That was the highest most-active contract settlement since Feb. 12, FactSet data show.