L82 II". '/'. SokaUer — Ferritungstite, a Nexo Mineral. 



The ratios deduced herefrom are shown in the following 

 table : 



Ratios of analyses of ferritungstite. 

 1 2 



WO, -16 or -94 -15 or -8S 



Fe a 3 -IV " 1-00 -IV " 1-00 



H a O 1-03 " 6-06 1-16 " 6-82 



These ratios are close enough to 1 : 1 : 6 to show that the 

 formula for ferritungstite is Fe„0 3 .W0 3 .6H.,0. Below are 

 shown the two analyses with the insoluble matter deducted and 

 recalculated to 100 per cent, compared with the theoretical 

 values calculated from the formula Fe 2 3 .W0 3 .6H a O. 



Comparison of analyses with calculated composition. 



Analysis 1 Analysis 2 Calculated 



W0 3 45-1 42-6 46-4 



Fe 2 3 32-3 32-5 32*0 



HO 226 24-9 21-6 



100-0 100-0 100-0 



The mineral is different from any described and the new name 

 proposed, ferritungstite, shows its chemical relation to ordi- 

 nai-y tungstic ocher or tungstite. 



Chemical Laboratory. 

 U. S. Geological Survey. 



