Silver prices settled up 16 cents to $18.59 while copper added 3 cents to $3.33. Gold mining stocks, an alternative way to buy gold, were mixed. Yamana Gold ( AUY) was popping 2.93% to $10.18 while Freeport McMoRan Copper & Gold ( FCX) rallied 3.84% to $73.34. Other gold stocks Agnico-Eagle ( AEM) and Eldorado Gold ( EGO) were trading at $62.27 and $18.07, respectively. -- Written by Alix Steel in New York.