TORONTO, Nov 13 (Reuters) - Canada's main stock index slipped to a two-month low on Tuesday, dragged down by resource and financial shares, as investors fixated on fears of a fiscal crisis in the United States and economic turmoil in Europe. The Toronto Stock Exchange's S&P/TSX composite index unofficially closed down 56.80 points, or 0.47 percent, at 12,134.66.