NOTES ON WOLFRAMITE, BERAUNITE, AND AXINITE. 



By Edgar T. Wherry, 



Assistant Curator, Division of Mineralogy and Petrology, United States National Museum. 



OBSERVATIONS ON WOLFRAMITE. 



The studies herein presented were undertaken at the suggestion 

 of Mr. Frank L. Hess, of the United States Geological Survey, who 

 desired information as to the composition of these two occurrences 

 of wolframite. 



No. 1 is a large specimen in the exhibition collection of the Museum 

 (Cat. No. 80179), labeled "Cornwall, England," although unfortu- 

 nately with no statement as to the exact mine or district from which 

 it came. It shows, however, the characteristic features of the min- 

 eral as found in that region, occurring as long bladed crystals, with 

 granular chalcopyrite, in white vein quartz. Along cracks in the 

 solid wolframite a yellowish powder is developed, which apparently 

 represents an alteration product, although the amount is too small 

 to determine its character. 



No. 2 is a mass about 6 by 9 by 12 cm. in size, showing a very 

 black wolframite intimately associated with bright green chrysocolla, 

 with here and there between the two, as well as throughout the wol- 

 framite, streaks of an olive green, waxy, copper tungstate mineral. 

 The associated gangue minerals are microcline and gray quartz, the 

 occurrence being evidently in a pegmatite vein. It came from Cave 

 Creek, north of Phoenix, Arizona, and was presented to the Museum 

 by Mr. S. H. Brockunier, through Mr. Hess (Cat. No. 87283) . 



Material for analysis was selected from portions free from visible 

 impurities, finely powdered and dried in a dessicator over sulphuric 

 acid. Preliminary trials of the method of distillation in a stream 

 of sulphur monochloride mixed with chlorine, recently recommended 

 by Bourion,^ gave rather unsatisfactory results in that it was ex- 

 tremely difficult to recover all the tungsten, some of it sticking to 

 the glass apparatus, and further, although most of the manganese 

 and all the silica, calcium, copper, and magnesium remained behind 

 in the boat, some iron was also left, so that it was necessary to run 



1 Ann. chim. phys., ser. 8, vol. 21, 1910, p. 87. 



Proceedings U. S. National Museum, Vol. 47— No. 2060. 



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