192 W. T. Schaller — California Minerals. 



amblygonite. The mineral usually occurs pure ; very rarely 

 small amouuts of lepidolite are present with it. Frequently 

 broad cleavage faces with irregular outlines can be seen. The 

 color is white and in thin pieces the mineral is translucent. It 

 fuses easily, coloring the flame red, and in powder is difficultly 

 decomposed by sulphuric acid. 



An analysis of a specimen kindly presented by Mr. Gr. F. 

 Kunz gave the writer the following results : 



P 2 5 48-83 



A1 2 3 33-70 



Fe 2 3 -12 



MnO _.. _ -09 



MgO -31 



Li 2 _. 9-88 



Na 2 -14 



H 2 5-95 



F 2-29 



Ti0 2 none 



101-31 

 LessO... -96 



100-35 



Regarding fluorine and hydroxyl as isomorphous, in the 

 specimen analyzed the latter greatly predominates over the 

 fluorine. The water was determined by igniting the mineral 

 with lead oxide, previously heated nearly to fusion. Three 

 determinations gave the loss of weight, due to the escape of 

 water, as 5*89, 6*01, 5*95 per cent. The loss of the mineral on 

 ignition was 8-03 per cent, equalling the sum of the water and 

 fluorine content. 



Boothite. 



A specimen of a pale blue copper sulphate was collected at 

 the copper mine near Campo Seco, Calaveras Co., California, 

 by Mr. James Wise, and kindly presented to the writer for 

 investigation. The pale blue color suggested that the mineral 

 might be boothite instead of the more frequently occurring 

 chalcanthite. The results of a chemical analysis have shown 

 that the mineral is boothite, thus affording a second locality 

 for this interesting mineral. Careful quantitative determina- 

 tions of hydrous copper sulphates will probably show that the 

 heptahydrate is not so rare as may be supposed. 



The mineral from Campo Seco occurs massive, showing no 

 crystalline structure. The average of several determinations 

 afforded the following results : 



