Some months ago the writer received from Charles G. Earle of Haliburton, Ont., a few ounces of small, loose crystals which electroscope tests showed to possess considerable radioactivity, and which were immediately suspected of being either ellsworthite or betafite. The crystals received are free from gangue but are more or less coated with a yellowish brown decomposition or resorption product, as well as with small crystals of apatite, which along with calcite may also be included in part or completely within the crystals themselves. One fragment of a crystal, however, was entirely free from any superficial coating or alteration and showed clean, sharp, bright faces. The crystals vary from slightly less than 1/4 inch to 1/2 inch in diameter and in general exhibit a rounded octahedral habit, with the octahedron most prominent in combination with small cube faces and with rather frequent occurrence of small faces of the dodecahedron and the tetragonal trisoctahedron m(311). Fig. 1. Owing to the rounding of edges and smaller faces, the octahedron and cube are sometimes the only definitely distinguishable forms. Several crystals however were in part sufficiently sharp and well developed to permit measurement and identification of the faces indicated in the figure. Other crystals are simply rounded, small ball-like masses on which the faces cannot be definitely identified.

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