J. L. Smith — Examination of An 



ntense Mack of the samarskite, but of a brownish color with a 

 streak and powder much lighter than that oi samarskite; and in 

 pushing- my researches further, the mineral was obtained still 

 lighter, of a hair brown color, the powder being of an ash color. 

 In thin fragments it is translucent; the fracture issubconchoidal, 

 but in most instances irregular, with a resinoid luster. 



Its aspect made it very evident that it was something different 

 from the samarskite. and an examination proved this opinion 

 correct, and established its true mineralogical position. 



No crystals have been found, so it is not possible to establish 

 ty in crystallization with euxenite; but all its other 

 physical and chemical properties are those of that mineral. 



The spec I specimens 



was respect iv ; t '593, 4*620, 4*642. On analysis it was found 



Columbic acid 54-12 Uranium oxide 9-53 



Tungstic and stannic acid.. ->\ Manganese protoxide. . . -08 



Yttrium and cerium oxides 2410 Iron protoxide '31 



Lime 5-53 Water..- 5-70 



The columbic acid was tested most carefully for titanic acid, 

 both by fusion with bisulphate and with carbonate of potash, 

 but none of it could be detected; only 5 milligrams of a resi- 

 due was obtained as a result in these analyses, and it is well 

 known to analvsts that this is most probabK attributable to 

 columbic acid. 



I need hardly insist that the above properties belong to the 

 mineral euxenite: they approach! • Tromoen, 



analyzed by Strecker, except, that this chemist makes as much 

 as sixteen per cent of the metallic acids to be tit 

 This euxenite represents a purer type of acolumbate t 

 of those of which analvses are given, while it is ala i 

 lor the small-quantity of iron oxide in it: being a hydra ted 

 columbate i id lime. 



llatchettolite — a new Columbate. 



This is an additional one of the series of columbic acid min- 

 erals found with the samarskite of North Ci 



- first called by Mr. Eals: •T^' 1 /' 



that he had diligentlv uncovered from the 

 spar, which had to all appearance some c 

 samarskite. He had sent two or three o\ 

 Edward S. Dana some time before, and this last mineralogist 



