A. H. Means — New Mineral Occurrences 



Per cent 



Bi 2 3 28-17 



As _ 10-59 



from Utah. 



Molecular ratio 

 0-061 

 0-046 



FeO, 



3-88 



0-024 



Al 



0-44 



0-004 



CuO 



CaO 



so 3 



H 



0-12 



0-62 



0-46 



2-14 



0-002 



o-ooi 



0-006 

 0-119 



PO 



0-04 



o-ooo 



Sb 0, 



1-26 



0-004 



PbO 



1-12 



0-005 



129 



1 



0-092 



0-098 

 0-046 



2-0 



From the mineral association as observed in the district the 

 following minerals were assumed to be present and the molec- 

 ular ratios representing them deducted. They are : anglesite, 

 PbS0 4 ; mixite, 20CuO.Bi 2 O 3 .5As 2 O 5 .22H 2 O ; limonite, 2Fe 2 3 . 

 3H 2 (2'0 per cent present as previously mentioned) and jaro- 

 site. The remaining Fe 2 3 , CaO, Sb 2 3 , A1„0 3 , are considered 

 isomorphous with the Bi 2 3 . 

 There now remain : 



Bi 3 3 ... 0-061 



Fe 2 3 0-012 



CaO 0-011 y 



Sb 2 3 0-004 | 



A1 8 8 -. 0-004 J 



H 2 0.. 0-098 



As 2 5 0-046 



This gives a formula of 2Bi 2 3 .As 2 6 .2H 2 0. 

 Considering now, as an alternate formula derived by assum- 

 ing all the water as water of crystallization, i. e., including the 

 0*38 per cent water previously mentioned as hygroscopic mois- 

 ture, there result : 



Bi 2 3 1-561 



Fe s 3 0-012 



CaO 0-011- 



Sb 2 3 ._ 0-004 



A1 S 3 0-004 j 



H 2 0.. 0-119 



As 2 0. 0-046 



This changes the previous formula to the following 4Bi„0 3 . 

 3As 2 5 .5H 2 0. Either formula appears to fit the data equally 

 well, depending upon the manner in which the question relat- 

 ing to hygroscopic water and water of crystallization is.decided. 



The properties of the mineral may be briefly described as 

 follows : Color — yellowish green with tinge of brown. Habit 

 — cryptocrystalline aggregates. Hardness — not determined 

 because of pulverulent condition of the sample. Probably about 

 3 - 0. Specific gravity— 5*70. as determined by pycnometer. 



Am. Jour. Sci. — Fourth Series, Vol. XLI, No. 241. — January,'1916. 

 9 



1 



> 



0-092 



0-119 

 0-046 



5-2 



1' 



