The August contract for gold rose $32.50, or 2.6 percent, to $1,279.90 an ounce. Gold has risen 5.5 percent this week.
Gold bulls welcomed remarks from Bernanke late Wednesday indicating that the Fed was not about to pull back on its support for the U.S. economy any time soon. The Fed's policies of keeping interest rates low and buying bonds have supported gold prices because they could increase the risk of inflation and a weaker dollar, increasing gold's appeal as an alternate store of value.
September silver rose 79.1 cents, or 4.1 percent, to $19.956 an ounce.
Copper for September delivery rose 8.65 cents, or 2.8 percent, to $3.1775 a pound. October platinum rose $39.50, or 2.9 percent, to $1,407.60 an ounce. September palladium edged up $4.40, less than 1 percent, to $718.20 an ounce.
Energy prices closed mostly lower. U.S. benchmark crude fell $1.61 to close at $104.91 a barrel.
In other energy trading, wholesale gasoline rose 1 cent to settle at $3.02 a gallon, natural gas fell 7 cents to settle at $3.61 per 1,000 cubic feet. Heating was little changed at $3.00 a gallon.
Crop prices rose.
Wheat for September delivery rose 4 cents to $6.83 a bushel, December corn rose 5.5 cents to $5.27 a bushel and November soybeans rose 6 cents to $12.9075 a bushel.