Gold futures on the COMEX division of the New York Mercantile Exchange went down for the fourth session in a row Friday, ending the week with a loss of 5.6 percent.
The most active gold contract for December delivery dropped 22 dollars, or 1.65 percent, to settle at 1,308.6 dollars per ounce.
It's gold's lowest settlement since Aug. 7.
As Federal Reserve Chairman Ben Bernanke will retire soon, investors are weighing the likely nominees for the U.S. central bank. The attitude of the new chairman will be vital to the continuance or withdrawal of the stimulus policy.
Economic figures released Friday were positive to gold, but failed to prop up gold prices. The University of Michigan-Thomson Reuters consumer-sentiment index fell to a preliminary September reading of 76.8, the lowest level since April, from a final August reading of 82.1.
The U.S. Commerce Department said retail sales climbed by seasonally adjusted 0.2 percent in August, the smallest increase since April and below the market forecast.
Market analysts believe that the sharp loss in gold prices this week comes mainly out of technical selling, as there has been no significant decrease in global physical demand for gold.
Some investment banks have updated their outlooks for gold this week: HSBC raised its 2013 average annual forecast for gold prices to 1,446 dollar from 1,396 dollars per ounce, and kept its 2014 projection unchanged at 1,435 dollars, while Goldman Sachs predicted that gold prices will drop below 1,000 dollars an ounce next year, as against its previous 12-month forecast of 1,175 dollars per ounce.
Silver for December delivery lost 42.9 cents, or 1.94 percent, to close at 21.72 dollars per ounce. Platinum for October delivery rose 1.8 dollars, or 0.12 percent, to close at 1,444.5 dollars per ounce.