300 Hillebrand and Washington — Minerals from Utah. 



clinoclasite. Crystals of olivenite are frequently scattered 

 over its surface, which shows often a somewhat satiny sheen 

 due to minute crystal facets. Hardness 4 - 5. Sp. gr. unde- 

 termined. Because of its intimate association with azurite and 

 olivenite it was very difficult to obtain pure material for analy- 

 sis. Sample I contained 3*90 per cent of insoluble matter, not 

 included in the analysis. Sample II was composed of a small 

 lot of vitreous crusts, the only ones of the kind observed, which 

 had been collected before shipment of the specimens and were 

 thought to be erinite by Mr. Pearce, whose partial analyses 

 of material similar to sample I are added, for comparison, under 

 III. 



I. II. in. 





Hillebrand. 



d, % 



Pearce. 



6. 



CuO 



57-67* 



57-51 



56-56 



57-43 



ZnO 



1-06 



059 











CaO 



0-32 



0-51 



043 





MgO 



tr. 



tr. 









As 2 6 



33-53 



31-91 



32-07 



32-54 



P 2 5 



o-io 













H 2 



7-22 



9-15 



6-86 



7-67 



Fe 2 3 



0-14 



0-20 



0-85 







S0 3 







_ __ 



tr. 







100-04 99-87 96-77 97"64 . 



Analyses I and II, and presumably those of Pearce, show the 

 composition of air-dried powder. Sample I lost 0'67 per cent 

 H 2 over sulphuric acid and a total of 0*78 per cent at 100° C. 

 At 280° C. the total loss was 1*14 per cent, leaving 6*08 per 

 cent firmly combined. Sample II lost 2'06 per cent over sul- 

 phuric acid and a total of 3*22 per cent at 2 "80° C, leaving 5*93 

 per cent firmly combined. The molecular ratios, including all 

 the water, are : 





CuO (CaO, ZnO) 



As 2 5 (P 2 5 ) 



H a O 



I. 



5-08 : 



1-00 : 



'2-74 



II. 



5-34 : 



1-00 : 



3-66 



III. (mean) 



5-13 : 



1-00 : 



2-87 



If the weakly combined water be excluded from both I and 

 II the ratio is brought considerably nearer to that derived from 

 Turner's approximative analysis, f i. e., 5 : 1 : 2. 



It is uncertain whether Turner's sample was air-dried or 

 heated to 100° C. 



3. Tteolite. (?) 



Regarding the identity of this species some doubt exists, as 

 the analytical results obtained do not agree with those given by 



*Mean of 57-61 and 57-74. 



\ Edin. Journ. Sei., ix, 95, 1828. Phil. Mag., iv, 154, 1828. 



