Benchmark U.S. crude dropped 2.6 percent to settle at $51.49 a barrel in New York. Brent crude, used to price international oils, slid 2.4 percent to close at $60.06 per barrel.
Gold gained 0.1 percent to $1,243.60 an ounce. Silver fell 0.5 percent to $14.51 an ounce. Copper dropped 1.1 percent to $2.74 a pound.