Gold gained $23.60 on the Comex division of the New York Mercantile Exchange Friday as worries persisted about U.S. debt negotiations. Gold closed at $1,751.80 as the dollar index fell 0.58 percent to 80.23. Silver added 7.67 cents to close at $34.11. The dollar gained against the Indian rupee, South Korean won, Taiwanese dollar and Egyptian pound, falling against other currencies. The euro rose to $1.297 Friday from $1.2884 Thursday. Against the yen, the dollar fell to 82.38 yen, compared to 82.46 in the preceding session.