124 



C. II. Warren — Miner alogical Notes. 



crystalline particles of a delicate pink color, imbedded in gyp- 

 sum and associated with a little atacamite. The mineral was 

 first carefully selected from all material of a green color by 

 hand picking, and was then crushed and sifted to a uniform 

 grain, and treated with the heavy solution to separate the 

 lighter portion. The heavy portion when examined under the 

 microscope was apparently very pure. The specific gravity 

 was found to be 3*874, and an analysis gave the following 

 results : 



C0 2 36-89 



FeO -. 



ZnO _.. 39 



CoO 



MnO . 

 MgO . 

 CuO_. 



Cl 



HO ._ 



I. 



II. 



Average. 



Ratio. 



6-89 



36-99 



36-94 



•839 -839 



•33 



•33 



•33 



•004 "J 



9-03 



39-01 



39-02 



•481 | 



0-27 



10-24 



10-25 



•126 ^'838 



3-40 



3-32 



3-36 



•047 | 



7-00 



7*43 



7*22 



•180 J 



1-03 



1-67 



1-65 





•11 







•11 





1-24 



1-34 



1-29 





100-17 



Regarding the small amounts of CuO, H 2 and CI as im- 

 purities, resulting possibly from a slight admixture of atacamite, 

 the ratio of C0 2 :(Zn+Co+Mn + Fe+Mg)0 is -839 : '838 or 

 almost 1 : 1, indicating that the mineral is a normal carbonate, 

 and essentially a zinc carbonate, smithsonite, in which the zinc 

 is partially replaced by cobalt, manganese and magnesium. 



In conclusion the author desires to express his thanks to 

 those gentlemen, whose names have been mentioned in this 

 paper, for their kindness in placing their specimens at his 

 disposal, and especially to Prof. S. L. Pentield for the valuable 

 advice and assistance which he has rendered during the 

 investigation. 



Laboratory of Mineralogy and Petrography, 

 Sheffield Scientific School. 





