600 Ford and Bradley — Hetmrolite from Leadville. 



Art. L. — On Hetmrolite from Leadville, Colorado ; by 

 W. E. Ford and W. M. Bradley. 



In November, 1911, a small specimen of a zinc-manganese 

 oxide, coming from the Wolftone Mine at Leadville, Colorado, 

 was sent to Prof. E. S. Dana by Mr. W. C. Wetherill, at that 

 time consulting engineer for the Empire Zinc Company. In 

 the letter that accompanied the specimen was a copy of a pre- 

 liminary analysis of the mineral made by Mr. Glenn Haigh 

 for the company. This analysis, together with the physical 

 properties of the mineral, indicated that it might be a new 

 species. Prof. Dana kindly turned the matter over to the Min- 

 eralogical Laboratory of the Sheffield Scientific School for 

 examination. Unfortunately Mr. Wetherill died before an 

 opportunity offered to carry out the investigation. Later, in 

 May, 1912', Dr. William S. Ward, curator of the Mineral Col- 

 lection in the Colorado Museum of Natural History in Denver, 

 wrote further about the matter and generously donated a h'ne 

 specimen of the mineral. Mr. Wetherill originally suggested 

 that, if the substance proved to be a new species, it be named 

 after the property on which it was found ; Dr. Ward, in his 

 letter, made the counter suggestion that it be named after Mr. 

 Wetherill, who first called attention to it. On detailed exam- 

 ination, however, the mineral has proved to be identical with 

 hetserolite, previously described from Stirling Hill, Sussex 

 County, N. J., and consequently both of these suggestions have 

 had to be disregarded. 



Hetserolite was first described in 1877 by Dr. Gideon E. 

 Moore in a brief notice published in this Journal.* The essen- 

 tial points of his description follow : It was found in an 

 ochreous limonite with chalcophanite. It occurred in botry- 

 oidal coatings of columnar radiating structure. Its hardness 

 was 5, and its specific gravity 4933. Its luster, metallic to 

 submetallic ; color, black ; streak, brownish black. It was 

 infusible ; in the closed tube it gave a little water ; with fluxes 

 it gave the reactions for manganese and zinc. No analysis was 

 quoted, but the statement was made that the formula was that 

 of a zinc hausmannite, ZnO.Mn 2 3 . 



Because of the incomplete description, the mineral has been 

 considered a doubtful species, and was placed by Dana in the 

 System of Mineralogy in the Appendix to Oxides, f In 1910, 

 Prof. Charles Palache published an analysis;}; made in 1906 by 



* This Journal, xiv, 423, 1877. 



f System of Mineralogy, 6th ed., p. 259, 1892. 



% This Journal, xxix, 180, 1910. 



