A study of matildite from another occurrence in the Camsell River area, N.W.T. is reported. The mineral occurs as pure irregular grains in a deposit containing native silver, native bismuth and Co-Ni arsenides and in which galena has not been identified. Single crystal studies and reflectivity measurements confirm the hexagonal symmetry postulated by Geller and Wernick, but with the a-cell dimension doubled, yielding values of a = 8.12; c = 19.02A. Electron-probe microanalysis shows that the mineral is homogeneous with a formula of Ag (sub 0.95) Bi (sub 1.00) S (sub 1.97) which agrees very well with the ideal formula AgBiS 2 . Microhardness values (25-gram load) range from VHN 59 to 76.

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