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



was inclined first to refer it provisionally to pjrochlore, but 



finally on account of its high specific gravity suggested its pos- 

 sibl ■ r. lation to microlite. (See this Journal, March, 1876, page 

 204). No further steps having been taken to settle the charac- 

 ter of this mineral, I undertook 



fin' -hed me b\ Mr. IktNt.m, and also on a specimen I after- 

 ward found in carefully examining the altered gangue of the 

 samarskite in my possession. 



The result has been the establishing of a new mineral of this 

 series, which I have called Hatchettolite, from the discoverer of 

 the element columbium. It occurs in regular octahedrons, but 

 of the six crystals that I have examined, all have the cubic 

 planes and the form 3-3, and E. S. Dana observed the same on 

 the crystals he examined. 



In referring to these modifications, I would state that, among 

 eight or ten crystals of pyrochlore seen by me I have never 

 observed them, although this last mineral is found with them, 

 as maybe seen in M. Kokscharow's magnificent work on Rus- 

 sian minerals. I could not detect any distinct cleavage. Its 

 - about 5: perhaps a little over. Specific gravity': 

 that of a fine small crystal was found to be 4*851 ; of small 

 fragments well selected from a large crystal that had mica in 

 some part of it. 4-785. Prof. Brush obtained (as quoted by E. 

 S. Dana) 4794. 



It is well to add here the specific gravity of a very fine 

 crysta of pyrochlore. veighing one and one-half grams; as 

 taken by mv-e'. it i- 4*l , .\ That of microlite — another octa- 

 hedral columbate — by Shepard and Hayes, is 5-484. 

 . Color of Hatchettolite.-- Yellowish brown with a grayish opa- 

 lescence : on heating to redness becomes of an opake greenish 

 yellow; luster resinous; fracture subconchoidal. 



Composition. — I made three analyses, the first two on frag- 

 ments from the specimens of Mr. Ralston, and the third from 

 a specimen in my own collection. The mineral was broken 

 into pieces from 2 to £ mm. in diameter, and then carefully 

 selected under the glass to avoid admixture of any other min- 

 eral. Thus selected it was found to contain : 



Columbicacid 66-01 67*86 67*25 



Tungstic and stannic acids. -75 -60 '91 



Uranium oxide. ... 15-20 15-63 16*01 



Lime 7-72 7-99 7*11 



Yttria and cerium oxide... 2*00 -86 -64 



Iron protoxide 2-08 2*51 212 



Potash -50 1-21 not estimated 



Water— lost by heat 5-16 4-42 5*02 



