360 Supplement to Dana’s Mineralogy. 
{If the titanic acid ea pine with the bases (see Min.) the ratio is rig 15°07, 
Nar allowing for so umbic acid with the titanic acid, may poir io 
:8; this would give the gan R Cb or (#8, R3) Cb?, which is sean ets to 
hd of t setae ere is some approximation to the form of tantalite, the oc- 
curring pris m being 12 ise in euxenite, and 122° 54’ in ite; or, taki er 
view of their Apia positions, the angle 117° above may correspond to O: 3% in 
tantalite which is 117° 2’, But without eee crystallographic examinations it 
would be premature to assert a near relation.—p.] 
Fevpsrars [p. 228]—A review of the various ag of aes 1 oer of Ain 
feldspar and a lite fami =e x minerals is bd hae by Scheerer in the Handw: 
d. Chemie, Braunschw 3, and an ractin Neues Jahrb, 1854, 593. 
paces [p. 184] Bs, A Sa of cle as been referred to gibbsite. 
Haidinger sustains it as a good species in the Recabesbat, xii, 188, giving the fol- 
i ; Usual i i i i ia, wi 
112°, Crystallization trimetric, optically biaxial. H.=15; G.=2'33 (Kenngott). 
pine tnge nay pearly. Color snow- -white, surface often ellowish. Composition ac- 
eer — S+1 OH = sulphuric acid 17°18, alumina 4415, wa 
ter 3866. ‘aihiysin ati 
1647 “RL 455 H 38127 = 9927 
pS mineral is _ near bpp ne particularly paraluminite, [p. 5091. 
di, by some refe jen to abeenaee has been exam- 
here it occurs with mie iolite, ee linic ; 
p wand Sack ection, and in a second inclined 129° tc to ‘the former, 
allel to the orthodiagonal. Color black ; Pa rown, Lustre 
weak; waxy or pearly. Subtranslucent. H.=5.0-5°5; G. ==3'4- 3°53. In a glass 
i : erik: apes 
tube sm er without much change. B.B. hs ‘a a semimetallic slag, which 
“s Fe Mn Ca Si H 
1282 407 6885 6°82 017 017 16°87 
Kenngott remarks that it is probably not vivianite, but more nearly related to the 
triphyline group. 
le saes aie a cars of this name from Iceland, mentioned in Glocker's Mineral- 
ogy, is AY imger psestigess to Kenngott (Min. Not., No. 12). H. =65; G.=2?4. 
Greenish black in the mass and vitreo-resinous. Composition according to v. B 
Si Al Fe ta Oa Na H(ign,) 
67470 13°375 1785 trace 8025 tr 1380 2870 9600 = 99405 
The eo ratio afforded for R, #, Si, a is 21:6: 344: 81. 
—The follo stad ecto Pent nate. 6.6 Mr. George J. Brus’ 
biznes sage cola ‘a letter date rate 1855. “ 
Note on Abich’s analysis of Fs Pte en Abich’s monograph 00 
the Spinel group,* the writer has observed some errors in a calculations of the 
analysis of Franklinitet which, it may be well to note. In this analysis, A —_ 
obtained 68°88 ¥e, which, considering the iron to exist in the mineral as as magnetit® 
(Fe #e), he erroneously m: makes equivalent to 47-52 Be a 21:34 Fe, the corre 
num , 
pees beet gen: Bat Me he calculated as « 40 grm. Mn; jit should be 
0515 grm. which on 2°690 grm. mineral use pr analy gives 12 19°14 Mn, or 2129 
¥n, instead of f 1644 Mn of 1817 Mn, Resist iy by A The analysis 
ce 2 et Oh ges 8 
4593 2067 2129 1081 O74 040 traces = 99°84. 
‘ ied 
ee ee) | 
