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Fourth Supplement to Danas Mineralogy. 115 



Clat. — A porcelain clay from Jacksonville, Ga., afforded J. "W. Mallet (this Jour. 



xxiii, 183): 



Comb'd Si Free Si Si 3Pe Ca, K,etc. fl undccomp. 



39-76 4'»5 38-92 078 103 13-38 0-90 = 99*61 



It corresponds nearly to the formula Si Si -f- 2H. 



Coal [p. 26 and II]. — Many analyses in Owen's Rep. GeoL Kentucky, 1856. 



CoLUMBPTE [p. 353 and II]. — Tlie columbite crystals of ihe greenland cryolite 

 locality have been measured with the following results by Descloizeaux (Ann. des 



Mines, [5], viii. 389). Observed planes : 0, H, \l, |T, t!, 1. /, 1-|, 2-|. 2-2, 1-3. 2-3, 



9-3, i3, 2-6, n, 2^, u; /: 7=100^ 40', : ^1=160^ 34' (observed 160^ 30'), ili^z 



140° 20' (observed 140° 0'), 1-3 : 1-3 (over brachyd. edge) 150° 18^ (observed 



150° 30'. 



Hermann announces (J. f. pr. Chem., Ixviii, 65] that the Bavarian columbite con- 

 tains tantalic acid (31*17 p. c.) along with columbic acid. He obtained for the atomic 

 weight of columbium 664-1. Ilmenium, he now merges_ in columbium, regarding 

 ilmenic acid as a compound of two columbium acids, or Sb Cb. The columbite of 

 Middletown afforded him, Tungstic acid 26, ^b 64-43, Cbl3-79, ga0 40, te 14 06, 

 Mn 5-63. % 0-49 = 99-06. 



According to Oesten (Fogg, xc, 617), the columbite of Bavaria does not contain 

 tantalic acid. 



The columbite of Middletown, Ct., has been analyzed by C. F. Chandler (Inaug. 

 Dissert.), with the following result (mean of two analyses) : 



^b 76-69 Sn 0'60 Fe 1823 Sin 3*14 Ca 0-48==;99-34 



giving the simple formula fi ^@b. G. = 5*583, in coarse powder 5-593. For the 

 Bodenmais columbite he obtained (ibid.) ; 



Sb 7502 Sn 0-47 W 0*39 fe 17-22 Mn 3-59 & 0*22 = 96-91. G.=5-97l 



CopiAPiTK [p. 388 and T, III.] — Kenngott [Mm. Forsch. 1855) unites the ahjpticite 

 m-id^fibrofcrrltc, under the oxygen ratio for Fe, S, £[, of 3 : G : 11=^6 Ss-f llfl, which 

 includes the copiapite analyzed by J. L. Smith (Suppl. I). 



3Iisi/[p. 389], according to analyses by Borcher, and Ahrend and Ulrich (in Hart- 

 mann's Zeit 1854, cited in Kenngott's Miu. Forsch. for 1854) has the same composi- 

 tion, observes Kenngott. with the true copiapite analyzed by Rose. Borchers spe- 

 cimens were pale yellow or citron-yellow, a loose aggregate of crystalline scales, 

 from near Qosiar. G.=2-14. H.= l*5. 



§ Pe 2 ii 



1. Borcher, crystallized, 3S-00 



2. Ahrend and U.,cryst'd. 39-44 



Pe 



2 



24-24 



6 80 



28-00 



2-00 



26-03 



236 



a 





80-06 - 



- 98-10 



SO-64 3 



= 100-08 



30-50 = 



~ 98 22 



3. " " earthy, 3807 26-03 2-36 1-26 



Tliey correspond to the formula Fe^ §*4" ^®fi" 



Copper [p. 17 and II]. — The native argentiferous copper of Lake Superior has 

 been found by Mr. Hautefeuille to contain mercury. He found in an analysis, 

 Copper 69-280, silver 5-453, mercury 019, gangue 25*248. 13856 kilograms of 

 copper gave him 10 906 of silver, 0*038 of mercury, with 50496 of the gangue. 

 Comptes Rend.. 1856, July, p. 166. 



Native copper in hexagonal prisms, pseudomorphous after aragonite, are de- 

 scribed by A. Kenngott in Pogg. c, 467. 



^ Cryolite [p. 97, and II, III.] — von Kobell, from his researches with the stauro- 



scope, has concluded that cryolite is dimetric. — J. f. pr. Chem., Ixv, 328, 



Daxbuuite [p. 212, and I, XL] — Kenngott points out a close relation between the 

 formulas of danburite and anorthite. Writing for boracic acid E^O', the analog 

 is perfect ; at the same time both are triclinia 



Datholitr [p. S34, and 1, 11, 111,]— Senarmont states (Ann. des Mines, [5],viii.4^7> 

 that when crystals are^ sliced precisely parallel to the terminal plan« 0, and exam- 

 ined by polarized light, the colors spread moat on one side instead of being uniform 

 around, showing that beyond doubt the prism ia obliq-ue and cot a right prism. 



If.- 

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t 



