J. L. Smith— Examination of American Minerals. 361 



minerals on the North American continent, they will be found 

 to range from Greenland in the north to Carolina in the south, 

 from Massachusetts on the east to Colorado on the west 



After these remarks in reference to the restoration of the 

 name columbium among the elements, replacing that of nio- 

 bium. I will detail my researches upon the more recently dis- 

 covered columbates. 



Cohtmbitefrom North Carolina. 

 This mineral has been found during the past few years at the 

 mica mines in Mitchel County, and in Yancey County near 

 Burnsville, in the State of North Carolina. It occurs in rocks 

 belonging to the same epoch as those in which the samarskite 

 was el ^covered, an 1 which will be mentioned more fully when 

 the latter mineral is described. 



There is nothing peculiar or striking in the crystalline form 

 of the mineral astound at this locality; many of the crystals 

 that have come under my observation have been compressed 

 and distorted, s is not un frequently the case with minerals 

 associated with mica. Most commonly I have seen it in irreg- 

 ular lumps weighing from five to one hundred grams. Sev- 

 eral phccs have been sent to me under the supposition that 

 they were tantalite, but in no instance have I found it to be the 

 case, the specific gravity never exceeding 5'5 to 5 - 6. 



The specific gravity 'of the i d both for 



the crystals and for the massive variety is as follows : 



Crystals 5-562 



Massive 5-485 



The analyses of both varieties show that they are chemically 

 identical. The average of several analyses which agreed very 

 closely, is: 



Massive. Crystals. 



Columbic acid* 80-82 80-06 



Tungstic and stannic acids . — 1 "02 1 '21 



Iron protoxide..--- 8 '' 73 14 | 14 



Manganese protoxide 8 ' 60 5 ' 21 



Copper oxide trace 



99-17 100-62 

 The distinctive peculiarity of the composition of this colum- 

 bite is tl manganese oxide compared with 



that of the - : "'•• lt bem o g reater tban 



that given in the amdvsis of any other columbite, 

 ft * I refer to the metallic ad; ' Y^fy^^^SS, 



and also becaust ' rati ° g the two adds haTO 



given satisfactory results in my hands. 



