W. T. Sclialler —The Alunite-Beiodantite Group. 361 



The formula of carphosiderite and apatelite* may be expressed 

 in similar form, the only difference being the slightly higher 

 water : 



Carphosiderite = H 2 0.3Fe a 3 .4S0 3 .6H 2 + 3H a O 



I would therefore propose that, until proven to be otherwise 

 by careful work, carphosiderite, apatelite, raimondite, pastre- 

 ite, cyprusite, and utahite be regarded as the same mineral 

 with "the formula ri.. 2 0.3Fe.,0 3 .4SO a .<iH !! 0, to which the name 

 carphosiderite be applied by right of priority. 



The compilation of analyses of these minerals, given in the 

 table below, shows their close chemical relationship and also 

 their general agreement with the formula 



H 2 0.3Fe 5 3 .4S0 3 .6H 2 0. 

 Analyses of Carphosiderite. 





Calcu- 

 lated 



Utahite 



Cyprus- 

 ite 



Pastreite 



Raimon- 

 dite 



Carpho- 

 siderite 



Apate- 

 lite 





1 



2 b 



1 



2 



1 



2 



HoO_-_ 



135 



935 



[1241] 



1106 



16-04 



13-95 



1740 



18-30 



18-48 



192 



S0 3 --- 



347 



28-45 



26-83 



35 34 



30-47 



3055 



36 08 



3182 



30-18 



29-7 



Fe 2 3 - 



51-8 



58-82 



58-51 



4968 



4650 



52-80 



46-52 



49-88 



48-52 



40-0 



A1 2 3 . 



... 



— 



... 



3-89 



— 



... 



... 



... 



... 



110 



X 



... 



3-19 » 



2-19 c 



... 



6-40 d 



2-68 e 



... 



... 



2-72 f 



--- 





1000 



99-81 



100-00 



99 97 



9941 



99-98 



100-00 



10000 



99-90 



999 



Density 









1-7-1-8! 







319-3-22 



2-49 



2-73 



3-2 



a As 2 5 . 



b Arzruni and Thaddeeff. Zeitschr. Kryst., vol. xxxi. p. 244. 



c Insoluble. 



d Si0 2 , 2-40 ; As 2 5 , 1-86 ; PbO, 1'25 ; (A1 2 3 , MnO, CaO), 0'i 



e As 2 5 , 205 ; (A1 2 3 , CaO, sand), 0-63. 



f P 2 5 . 



Miscellaneous Notes. 



Though the members of the group are uniaxial rhombo- 

 hedral, optical anomalies indicating biaxiality have been noted 

 for several of the species : for a stilphate (jarosite), a phos- 

 phate (hamlinite) and a compound sulphate-sulphate (hinsdal- 

 ite). Jarosite has been described as snowing optical anomaly 



* Apatelite is only an aluminous carphosiderite. 



Am. Jour. Sci.— Fourth Series, Vol. XXXII, No. 191.— November, 1911. 



27 



