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



Journal, March, 1876, page 201; he also first published an 

 account of the region in which it is found, an 1 ga\ e i n a< < >uut 

 of the associated minerals. 



Composition. — This mineral from North Carolina has already 

 been examined three times. In 1852, Prof. T. Sterry Hunt 

 examined a small piece of the mineral, less than one gram, said 

 to have come from Kutherford County ; again, Miss Ellen H. 

 Swallow has given a most excel- samarskite 



from Mitchel Co. agreeing with those made by myself as nearly 

 as the analyses of such a mineral can be expected to do when 

 made on different specimens ; and finally, Prof. Allen has made 

 an analysis, which is to be found on p. 340 of Dana's Text Book 

 of Mineralogy (March, 1877). The following are the analyses, 

 (1) of myself, (2) of Miss Swallow, and (3) of Prof. Allen, 

 (i) (2) (3) 



Columbi'c acid 55*13 j . 37"20 



Tantalicacid - \ 54Jb 18-60 



Tungstic and stannic acids. . 0-31 0-16 0-06 



Yttria ..14-49 12-84 1445 



Cerium oxides* 4-24 5-17 4-25 



Uranium oxide 10'96 9*91 12 # 46 



Manganese protoxide 1-53 10-91 0-75 



Iron protoxide .. . 11*74 14-02 10*90 



Insolubl 



le residue from cerium oxide 1-25 



99-12 100-36 



The late Heinrich Rose, in describing the samarskite of 

 Miask, gives an analysis by Finkener and Stephans,+ winch dif- 

 fers from the analysis previously made, as well as from those 

 now detailed, indicating the presence of four per cent zircon ia, 

 and six per cent of thoria. The announcement of the presence 

 of the latter named oxide has been one of the causes of the 

 delay of my publishing this paper, for \ desired if possible 

 to verify the results of Finkener and Stephans It is only 

 recently that I have obtained a few grams of pure Miask sa- 

 marskite, from the School of Mines of St. P. t. -rsbur-. thmu-h 

 Prof. Norpe, but all of this, except about U grains, was lost 

 after reaching me, so I have not been able'tcV do more than 

 make an ipa on; and this examination shows 



that there is some difference in tl m those in 



the North Carolina specimens, the exact d t -rriiin itiou of which 

 I must postpone for 'some future occasion. 



* I record these oxides as cerium oxides, but I am not altogether satisfied in 



t Verhandlu 



. Pet., 1863, 1 



