150 Hoffmann — New mineral occurrences in Canada. 



ings resulting from the drying up of the soft material of the 

 concentric rings of interglobular spaces in the ivory of the 

 tusk of a mammoth which was found at a depth of some fifteen 

 feet in a surface bed of dark frozen swamp-muck overlying 

 stream-gravels on Quartz Creek, a tributary of Indian River 

 which flows into the Yukon some twenty miles south of Dawson 

 City, Yukon district, in the Northwest Territory. 



The material occurred in the spaces in question in the form 

 of readily removable plates of from one to two millimeters in 

 thickness, which were at first colorless and transparent, but, 

 on exposure to the air, became white and lost their trans- 

 parency. In the closed tube it gives off water and ammonia 

 and becomes opaque. When heated before the blowpipe it 

 imparts a green color to the inner flame, and fuses at about 

 3 to a white enamel which, when moistened with a solution of 

 cobalt nitrate and reheated, assumes a beautiful pink color. 

 It is slightly soluble in water, and readily and completely so in 

 cold, dilute hydrochloric, nitric or sulphuric acid. 



Its analysis afforded Mr. R. A. A. Johnston the following 

 results : 



Phosphorus pentoxide 38*53 



Magnesia ___ __ 21*93 



Ammonia , 1*94 



Water, by difference..... 37*18 



Carbon dioxide 0*42 



100*00 



These figures afford a ratio closely agreeing with the follow- 

 ing formula : 



(HMgP0 4 + 3H 2 0)-f2(NH 4 MgP0 4 + 6H 2 0)+atrace of MgC0 3 

 Newberyite. Struvite. Magnesite. 



3. Schorlomite. 



A mineral which, as the result of an examination by Mr. 

 F. G. Wait, proves to be this species, has been met with, in 

 masses of considerable size, as an accessory constituent of the 

 nepheline-syenite rocks of Ice River, a tributary of the Beaver- 

 foot which flows into the Kicking Horse'River, in the Rocky 

 Mountains, province of British Columbia. 



It is massive, without cleavage; the color is velvet-black, 

 here and there tarnished blue, and occasionally with pavonine 

 tints ; that of the streak, hair-brown ; the luster is vitreous ; it 

 is brittle ; the fracture is irregular, occasionally subconchoidal ; 

 it is opaque ; fuses quietly at 3 to a black enamel ; has a hard- 

 ness of 6*5, and a specific gravity, at 15*5° C, of 3*802. Its 

 analysis afforded : 



