Gold up slightly; copper down on session

December gold added $1 to $1,142.20 per troy ounce in New York trade Thursday after going lower earlier as the US dollar strengthened.

December silver was also higher at the close of floor trade in New York after declining during the morning session, adding 5 cents to $18.46 per troy ounce, while January platinum fell $8.10 to $1,443.90 per troy ounce.

The growing demand for gold, which has pushed prices to record highs, has resulted in a much higher output of gold coins by U.K and U.S. mints.

The U.K.’s Royal Mint saw production more than triple to over 100,000 ounces in the first three quarters of the year, while the U.S. Mint doubled sales in the first nine month of 2009 to 954,000 ounces.

Additionally, Harrod’s department store in London began selling gold in coins and bars in October.

Among base metals, copper prices were lower as March contracts in New York dropped 3 cents to $3.11 per pound while three-month contracts on the London Metal Exchange fell $70 to $6,810 per tonne.

Declines in copper prices might have gone further, but BHP Billiton (LSE: BLT) said it would “evacuate” its Spence mine in Chile, the site of a 38-day strike, due to alleged sabotage by workers after talks to end the strike broke down.

Most other base metals also saw prices drop in London on the stronger dollar.