Hoffmann — New Mineral Occurrences in Canada. 44' 



Art. XLYII. — On Some New Mineral Occurrences in 

 Canada ; by G. Che. Hoffmann, of the Geological Survey 

 of Canada. (Communicated by permission of the Director.) 



1. Datolite. 



A specimen of a mineral was recently submitted to the 

 writer for identification, which had been met with by Mr. 

 Bush Winning in some abundance in the workings of the 

 Daisy mica mine on the ninth lot of the first range of the 

 township of Derry, Ottawa County, in the Province of Quebec. 

 This mineral proved, on examination by Mr. R. A. A. Johnston, 

 to be datolite. 



Mr. R. L. Broadbent has since visited the mine in question 

 and collected a fine series of specimens which not only fully 

 illustrate its mode of occurrence, but likewise its various 

 mineral associations. On transferring these specimens to me, 

 Mr. Broadbent drew my attention to some small white, occa- 

 sionally colorless, octahedral crystals which he had observed on 

 some of them. These crystals, more fully referred to further 

 on, were also examined by Mr. Johnston, and identified by 

 him as the somewhat rare mineral, faujasite, a species not 

 previously recognized as occurring in Canada. 



The datolite occurs in the form of hard, compact, irregu- 

 larly shaped, at times more or less nodular, masses some 

 of which are of quite small dimensions, while others are of 

 considerable size — one having been found which measures six 

 inches across and weighs thirteen pounds. It has also occa- 

 sionally been met with in the form of moist, plastic masses, 

 which on exposure to the air become crumbly and ultimately 

 fall to pieces, forming a loose earth. The masses in question 

 occur imbedded in a matrix composed of an association of 

 a light to somewhat dark greenish-gray, more or less weath- 

 ered, pyroxene, brown phlogopite, light grayish to white 

 cleavable calcite, grayish-white translucent to colorless trans- 

 parent quartz, and bluish-green, more rarely faint purplish, 

 yellowish and colorless fiuorite, with some intermingled pyrite 

 and pyrrhotite, and small quantities of barite, chabazite and 

 faujasite. 



The mineral is greenish-white to all but white in color ; is 

 almost opaque ; has a dull luster ; is brittle ; breaks with an 

 uneven to subconchoidal fracture — the fractured surface resem- 

 bling that of fine stone-ware (Wedgewood-ware). It has a 

 hardness of 5, and a specific gravity, at 15'5° C., of 2*985' 

 Before the blowpipe, it fuses, with slight intumescence, at 

 about 2 to a clear glass, simultaneously coloring the flame 



