Silver, palladium and platinum fell the most, despite scattered hints that housing and manufacturing might be picking up. That's another sign that the "fiscal cliff" is yanking markets around more than anything else this week.
Gold for February delivery lost $7.80 to close at $1,655.90 per ounce. March silver lost 26.5 cents, almost 1 percent, to $29.975 per ounce.
March copper slipped 1.15 cents to $3.5895 per pound. March palladium fell $8.20, more than 1 percent, to $700.30 per ounce. April platinum fell $14.40, almost 1 percent, to $1,521.60 per ounce.
U.S. stocks closed lower for the fifth day in a row, and stocks across Europe also closed lower.
Investors are anxious to see if Republicans and Democrats can hammer out a budget agreement before Monday night. If not, the U.S. will go over the so-called fiscal cliff, meaning big tax increases and cuts to government spending will start to kick in on Tuesday.
Most energy commodities also fell. In New York, benchmark crude fell 7 cents to $90.80 per barrel. Brent crude fell 18 cents to $109.83 per barrel.
Gasoline fell 2.14 cents to $2.7999 a gallon. Heating oil fell 2.75 cents to $3.0448 a gallon. The exception was natural gas, which rose 5.7 cents to $3.4690 per 1,000 cubic feet.
Prices for key agricultural commodities ended higher for March contracts. Wheat rose 6.5 cents to $7.7875 per bushel. Corn rose 2.5 cents to $6.94 per bushel. Soybeans rose 4 cents to $14.18 per bushel.