4 PKOCEEDINGS OF THE NATIONAL MUSEUM vol. 72 



Analysis, ratios, and theoretical composition of cariwtite from Aloab, Utah 



Analysis 



Ratios 



Theoretical 

 composition 



H2O 



CuO, PbO.-_ 



MgO 



BaO 



CaO 



KoO 





1.35 



Tr. 



.22 



None. 



.64 



9. 58 



0.075 



.011 

 . 101 

 .005 



.229 

 . 116 



2/3 



1X1. 008 



2X0. 996 

 1X1. 000 



1.4 

 10. 9 



NasO 



FesOs 



AI0O3 



UO3 



VoO, 



V.O5 



P2O5 





.35 



.04 



. 16 



65.62 



None. 



21. 12 



Tr. 



66.6 

 21. 1 



AS2O5 



M0O3 



Insol 





None. 



None. 



.32 







99. 40 





From these results it is readily seen that the mineral from Cane 

 Springs Pass is an unusually pure carnotite. It is interesting to 

 note the absence of barium 'and copper, elements reported by Hille- 

 brand in the finer grained carnotites, as well as of phosphorus, ar- 

 senic, and moij^bdenum. The lime content is appreciable, and since 

 no calcite could be detected in the analj^'zed sample it probably 

 belongs to the mineral where it replaces potash. If the lime is 

 calculated with the alkalies, the ratios come out very close to the 

 theoretical values. The soda content is so small as to be of doubtful 

 significance. 



It will be noted that the water content is much lower than that 

 ordinarily given for carnotite. The air-dried material carried a.. 

 water content of 1.36 per cent, while material kept over sulphuric 

 acid having a water vapor pressure of 19 mm. had a water content of 

 1.72 per cent. The water content is therefore quite variable, a char- 

 acteristic common to the members of the uranite groups. The water 

 content is not only determined by the vapor pressure of the water 

 but probably by the size of the grains as well. 



RADIUM— URANIUM RATIO 



Contributed dy Frank L. Hess 



It is not surprising, considering the geology of the veins, that lead 

 could not be determined chemically. Sufficient time had not elapsed 

 since the solution and redeposition of the carnotite for the disintegra- 



