a New Mineral from Peru. 199 



Total vanadium as V.,0 5 



86.07 





V 2 "0 4 





33.48 



V 9 5 





49.38 



CaO 





10.65 



Fe 2 0, + A1,0 3 





1.39 



H 2 0+ 





5.90 



100.80 

 Si0 2 and MgO not determined. 



It is certain that this mineral has hygroscopic qualities 

 very similar to the uranium micas and is strongly influ- 

 enced by atmospheric moisture or dryness. 



In regard to the 5.9% held above 105° C. the results 

 seem difficult to harmonize, but we have the definite asser- 

 tion of the chemist that when first analyzed in the winter 

 of 1921, the mineral was practically anhydrous. This is 

 supported by the senior author's statement that the min- 

 eral then gave no water in closed tube. Just what the 

 condition of the material was when formed in the deposit 

 is not easy to say. In view of the uncertainty still 

 attached to the part played by water in this mineral we 

 have decided to let the formula stand as based upon the 

 first and complete analysis. 



Par agenesis. — In places the black acicular crystals are 

 coated with a yellow powder, and sometimes larger 

 masses of an orange-yellow substance cover the terminal 

 edges or are embedded between the black prisms. This 

 orange mineral, which is easily soluble in water, was 

 identified as pascoite (Ca 2 V 6 1T .llII 2 0) and agrees in 

 its optical character with that substance. It is clearly 

 a product of hydration of melanovanadite. — [The above 

 by W. Lindgren.] 



It remained to examine more closely the dark altered 

 shale upon which the bunches of melanovanadite were 

 attached. 



Quite generally, this material gave a stong vanadium 

 reaction and also gave off more or less S0 2 in open tube. 

 It also contained organic matter. To test for the pres- 

 ence of native sulphur the powdered material was di- 

 gested with CS 2 . Upon evaporation the solution yielded 

 a resinous product but no sulphur. The residue was 

 washed with alcohol and leached with water. It gave a 

 yellowish solution containing vanadium doubtless from 



