Descloizites from new Localities. 437 



The third column of molecular ratios gives those values 

 after allowing for admixed vanadinite calculated on the basis 

 of the chlorine found. A further correction has probably to 

 be made for an admixed soluble hydrous (zinc ?) silicate, which 

 might make the ratio approximate more closely to 4 : 1 : 1. 



3. Lucky Cuss Mine, Tombstone, Cochise County, Arizona. 



Mr. W. F. Staunton, Superintendent of the Tombstone Mining 

 and Milling Co., and Mr. Frank C. Earle, assay er at Tombstone, 

 kindly placed at my disposal for examination specimens of a 

 vanadium mineral the identity of which had not been estab- 

 lished. It was found in the Lucky Cuss mine as an incrusta- 

 tion, sometimes half an inch thick, on quartz, showing more 

 or less botryoidal surfaces of an indefinable dull greenish color. 

 On a fractured surface the color is brown ; the luster is 

 resinous ; the structure granular, only occasionally diverging 

 fibrous ; the hardness 3'5 ; the specific gravity of sample 

 analyzed, containing a little impurity, 5 - 88 at 19° C. ; color of 

 powder lemon-yellow. Analysis gave the following results 

 after deducting 0'67 per cent of insoluble matter. 





57-00 





Molecular ratios. 





PbO 



•2556] "~ 







CuO .... 

 FeO 



11-21 



trace. 



}- - 448o 



•4385 



3-93 



ZnO 



4-19 



•0517 J 







Y0O5 



19-79 



•1084 ) 

 •0048 ^-1145 







As 2 5 ... 



1-10 



■1115 



1-00 



P 2 5 ____ 



0-19 



•0013 ) 







H 2 .... 



2-50 



•1389 



•1389 



1-25 



CI 



0-07 



•0020 







SiOo .... 



0-80 









CaO .... 



1-01 









MgO 



0-04 









K 2 .... 



o-io 









Na 2 ... 



0-17 









C0 2 



0-82 









98-99 



The low total is probably owing to a loss of zinc during 

 analysis. Calcite was present as an impurity, and as the C0 2 

 just suffices for the CaO and MgO these are rejected in con- 

 sidering the composition of the vanadate. The figures in the 

 third column of molecular ratios are found by allowing for 

 probably admixed vanadinite calculated from the chlorine 

 found. In another specimen a qualitative test for chlorine 

 indicated a greater admixture of vanadinite. As in the case of 

 the descloizite from Georgetown, New Mexico, previously 

 described, a further allowance has perhaps to be made for a 

 soluble hydrous silicate. There can be no doubt that the 

 general formula for the vanadate is that of descloizite. 



