JOURNAL 





OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. VII OCTOBER 4, 1917 No. 16 



MINERALOGY. — Minasragrite, a hydrous sulphate of vanadium. 

 Waldemar T. Schaller, Geological Survey. 



The blue efflorescence occurring on patronite at Minasragra, 

 Peru, was found to be a sulphate of vanadium and was named 

 after the locality. It occurs abundantly at Minasragra, ac- 

 cording to Mr. D. F. Hewett, 1 and also is forming at the present 

 time on many of the patronite specimens in museums. A large 

 specimen of patronite in the United States National Museum 

 had a considerable amount of the blue efflorescence on it and 

 furnished the material for the present investigation. 



In addition to the matrix minerals, such as patronite, quis- 

 queite, and the nickelic pyrite, bravoite, the specimen shows as an 

 efflorescence blue minasragrite, white tufts of prismatic crystals 

 of morenosite, glassy green equidimensional crystals of melan- 

 terite, and clear bladed crystals of gypsum. All of the efflores- 

 cent minerals have clearly been derived from the oxidation and 

 hydration of those forming, the matrix. • 



No measurable crystals of minasragrite were observed, the 

 mineral forming small mamillary masses and granular aggre- 

 gates with drusy surfaces, generally distinct from the other sul- 

 phates but in places penetrated by masses of morenosite needles. 

 Examined under the microscope, the minasragrite shows irregu- 



1 Personal communication. Abundant material, much purer than the origi- 

 nal sample, has now been obtained and an analysis of this better material will 

 be undertaken. 



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