578 



HESS AND schaller: pintadoite and uvanite 



Analysis and ratios of pintadoite 



The ratios of the analysis yield the formula 2CaO.V20^9H20. 



Uvanite is a brownish-yellow hydrous uranium vanadate. Its 

 mode of occurrence is similar to that of carnotite which it re- 

 sembles in general appearance, but it has not such a clear bright 

 yellow color. It has been found only at, and in the vicinity of, 

 Temple Rock on the San Rafael Swell, Emery County, about 45 

 miles southwest of Greenriver, Utah. It occurs in rocks which 

 are probably the -equivalent of the upper part of the Dolores 

 formation. Some masses of the new mineral are a centimeter 

 thick, but these are rather rare. The mineral occurs in sufficient 

 quantity to be of economic importance. 



Examined microscopically, uvanite is seen to consist of very 

 minute crystalline particles with a very high birefringence. The 

 mineral is not soluble in water but dissolves very quickly in a 

 solution of ammonium carbonate. 



The analysis by W. T. Schaller is as follows: 



Analysis and ratios of uvanite 



In deducing a formula from the analysis, some uncertainty is 

 felt in regard to the lime and potash. If these be present as ad- 



