JOURNAL 



OF THE 



WASHINGTON ACADEMY OF SCIENCES 



Vol. io JANUARY 4, 1920 No. i 



MINERALOGY. — Hausmannite in the Batesville district, Ar- 

 kansas.^ H. D. Miser and J. G. Fairchild, U. S. Geo- 

 logical Survey. 

 During the investigation of the manganese deposits of the 

 Batesville district by the senior author, beginning in 191 8, 

 particular attention was given to a manganese mineral that has 

 been previously classed as braunite. The mineral forms a 

 large part of the marketed manganese ore and, being entirely 

 free or almost free of chemically combined silica, differs in this 

 respect from the typical braunite that is found in this district, 

 as well as at practically all, if not all, other known localities. 

 The two accompanying analyses by the junior author, taken in 

 connection with the physical and optical properties of the mineral 

 under discussion, indicate that it is hausmannite. Since only 

 one other authentic occurrence^ of hausmannite in the United 

 States has been reported and since it is, as stated above, one of 

 the important ore-forming minerals of the Batesville district, 

 this paper regarding it has been prepared. 



The manganese ores of the Batesville district consist of oxides, 

 of which psilomelane, hausmannite, braunite, manganite, pyrolu- 



' Published by permission of the Director of the United States Geological Survey. 



- E. S. Larsen reports an occiu'rence from Plumas County, Cal. The optical 

 properties of the hausmannite from that locality are given on page 6. Dana, in 

 listing the occurrences of hausmannite in the System of mineralogy, 6th Edition, 

 says, "Also reported from Lebanon, Pa. (but very doubtful, Genth)." 



