Gold rallies for fourth session in row

Gold futures on the COMEX division of the New York Mercantile Exchange closed higher on Tuesday, rising for a fourth straight session, amid uncertainties about the global economy.

The most active gold contract for December delivery gained 3.6 U.S. dollars, or 0.33 percent, to settle at 1,107.70 dollars per ounce.

Gold on Tuesday got support from increasing uncertainties over the world economy after Chinese yuan fell sharply as the country adjusted exchange rate.

The People's Bank of China performed a one-off depreciation of the Chinese yuan, causing it to fall to a record low since April 2013, as part of a free-market reform. The goal is to improve China's "central parity system" to better reflect market development in the exchange rate between the Chinese yuan and the U.S. dollar. Following the change, the central parity rate of the yuan weakened sharply to 6.2298 against the U.S. dollar compared to 6.1162 on Monday, down nearly 2 percent.

Gold was put under a slight amount of pressure as the U.S. Dollar Index rose by 0.1 percent to 97.29. The index is a measure of the dollar against a basket of major currencies. Gold and the dollar typically move in opposite directions, which means if the dollar goes up, gold futures will fall as gold, measured by the dollar, becomes more expensive for investors.

Silver for September delivery fell 0.8 cents, or 0.05 percent, to close at 15.284 dollars per ounce. Platinum for October delivery rose 2.5 dollars, or 0.25 percent, to close at 992.30 dollars per ounce.