C>tJI^> 



Phillips — Gageite, New Mineral from Franhlin, N. J. 283 



Aet, XXXI. — Gageite, a New Mineral from Franklin, New 

 Jersey ; by Alexander H. Phillips. 



Attention has been drawn to the probable existence of 

 another new mineral from this locality by Frof. Fenfield in 

 his description of leucophoenicite,* but as very little of the same 

 material came to the surface from the mine until the fall of 

 1909, nothing further was ever done in the matter. For the 

 last six months Mr. R. B. Gage of Trenton, N. J., for whom 

 the mineral now described is named, has been collecting mate- 

 rial for an analysis. Through the aid of Col. W. A. Roebling 

 of Trenton, who was willing to sacritice his best specimen, '04: 

 of a gram of well-crystallized material were obtained, and used 

 by Mr. Gage with the results here given : 



Eatio. 



SiO^ 24-'71 -412 1-49 



MnO ._.. 50-19 •707'^ 



ZnO_ 8-76 -107 !> 1-109 4-00 



MgO 11-91 -295 J 



H„0 [4-43] -246 -9 



100-00 



Letting R stand for the metallic oxides, the ratio of SiO^ : 

 RO : HP is as 1-49 : 4 : -9, yielding the fonnula (RO), (SiO,\ 

 •2H„0. Just how the water is related to the oxides, there was 

 not enough material to determine, as in fact the water in the 

 analysis is determined by difference. A large amount of the 

 burden of error will therefore lie in that portion of the anal- 

 ysis ; it is certain, however, that there is considerable water in 

 the molecule. From the empirical formula, gageite would 

 seem to be closely related to leucoplioenicite, if not one of the 

 probable series mentioned by Frof. Fenfield. 



Before the blowpipe the clear crystals assume at once a light 

 bronze color, which darkens on further heating to a deep bronze, 

 or nearly black, biTt they do not fuse. In the closed tube it 

 yields water with the same change of color. The crystals 

 dissolve at once in warm dilute nitric acid ; upon heating this 

 solution after the addition of a little silver nitrate and a small 

 crystal of ammonium persulphate a very distinct permanganate 

 color is obtained ; a single small crystal will yield this test. 



All the specimens of gageite thus far obtained are from the 

 Farker Shaft. It is well crystallized, the crystals are clear and 

 colorless, with a high vitreous luster, delicate, acicular and hair- 

 like, often radiated and grouped in bundles extending out from 

 * This Journal, viii, 351, 1899. 



