Metals prices tumbled again Friday as traders remained concerned about a drop in Chinese demand and uncertainty about monetary policy in the U.S. China has rattled markets in recent days as top officials there say they'll clamp down on bank lending in an effort to slow rapid economic growth and prevent speculative bubbles. A slowdown in China's huge economy could push demand for metals and energy lower. Platinum, palladium and silver, which all have industrial uses, fell sharply. Platinum for April delivery dropped $47.60, or 3 percent, to settle at $1,544.50 an ounce. Palladium for March delivery dropped $13.85, or 3.1 percent, to $440.10 an ounce. March Silver fell 57.8 cents, or 3.4 percent, to $16.932 an ounce. Mark Hansen, director of trading at CPM Group, said commodities traders are also keeping a close eye on a looming vote in the Senate to confirm Ben Bernanke as chairman of the Federal Reserve, whose term expires Jan. 31. Though he is expected to keep his job, that decision is not as certain as previously thought. Any change in who heads the Fed could have a major impact on interest rates, which in turn could strengthen or weaken the dollar. The dollar is one of the primary drivers of commodities prices, especially gold. Most commodities are priced in dollars and tend to fall when the dollar rises, which make them less attractive for foreign investors. Gold for February delivery fell $13.5 to settle at $1,089.70 an ounce. It hit a one-month low of $1,081.90 an ounce earlier in trading. Benchmark crude for March delivery lost $1.54 to settle at $74.54 a barrel on the New York Mercantile Exchange. In other Nymex trading in February contracts, heating oil fell 4.4 cents to settle at $1.9416 a gallon, while gasoline lost 1.72 cents to settle at $1.9657 a gallon. Natural gas futures added 20.4 cents to settle at $5.819 per 1,000 cubic feet. Grain prices also fell. Wheat for March delivery fell 1 cent to $4.985 a bushel. Soybeans fell 2.5 cents to $9.515 a bushel, while corn fell 7.25 cents to $3.6475 a bushel. 