July 9 (Reuters) - Canada's main stock index dropped at the open on Tuesday, with the materials sector leading the declines as gold prices eased to a one-week low.
* At 9:30 a.m. ET (1330 GMT), the Toronto Stock Exchange's S&P/TSX Composite index .GSPTSE was down 40.01 points, or 0.24%, at 16,422.94.