362 J. L. Smith — Examination of American Minerals. 



Columbite from Colorado. 

 Among the magnificent and gigantic crystals of Amazou- 

 stone recently discovered in El Paso Co.,' Colorado — and so 

 energetically explored by A. E. Foote — some specimens were 

 shown me having small black acicular crystals imbedded just 

 beneath their surface, Carefully detaching them from the feld- 

 spar, by no means an easy task,' and examining the crystalline 

 form, and subsequently the chemical composition, I found them 

 to be columbite. A few small and well-marked crystals have 

 been detached : the largest was a flattened, imperfect crystal, 

 weighing one and one-half grams. Most commonly they 

 are only in the. form of black elongated specks. A small 

 amount of the pure mineral that was separated enabled me to 

 make out its composition, although I could not obtain enough 

 for a very careful quantitative examination. The ex; 

 made gave a very low specific gravity ; it was taken on '600 

 gram, and is 5*15. Analysis of -500 gram gave 



Columbic acid 7961 



Iron protoxide 14-14 



Manganese protoxide . 4-61 



Loss by heat . -50 



Samarskite. 



A few small specimens of this rare mineral from North Carolina 

 have been in cabinets for several years, but its exact locality 

 and the nature of its occurrence were first made known in 

 April, 1873, through the agency of Joseph Wilcox of I 

 phia, and subsequently by the investigations and collections 

 made by Eev. J. Grier Ralston of Norristown. Not having 

 visited the locality myself, I have obtained my information 

 concerning it from the above mineralogists. It is found in 

 Wiseman's mica mine, Greesy Creek Township, Mitch. 

 near North Toe River, North Carolina. It was obtained while 

 extracting the mica, principally in a kind of pocket in the 

 mine, the miners palling it black mineral. Mr. Ralston was vi .■ re- 

 active in having it collected, and in 1875, there had been accu- 

 mulated about 400 kilograms of I •■ as brought 

 away from the mine by him; since that time only 

 has been taken out of the mines, but in all probability, it will 

 be found again in more or less abundance. Prior to this dis- 

 covery, the largest pieces of samarskite, found in the Ural local- 

 ity, were of the size of hazel-nuts; these occur imbedded in a 

 reddish brown feldspar. 



Its geological position is in crystalline rocks, in what maybe 

 called a coarse granite; the minerals of which rock are not 



