Gold prices slipped on the Comex division of the New York Mercantile Exchange Wednesday in late trading with the dollar index up 0.21 percent. The dollar index rose to 81.54 on the International Exchange. Gold shed $6.70 to $1,663 per troy ounce. Silver lost 4 cents to close at $30.92 an ounce. The euro fell to $1.2531 from Tuesday\'s $1.2565. Against the yen, the dollar rose to 78.70 yen from 78.51 yen.