COMMISSION GEOLOGIOUE - Arkisto.gsf.fi
COMMISSION GEOLOGIOUE - Arkisto.gsf.fi
COMMISSION GEOLOGIOUE - Arkisto.gsf.fi
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Suomen Geologinen Seura. N:o 35. Geologiska Sällskapet i Finland. 29<br />
BLANFORDITE<br />
MANGANARFVEDSONITE<br />
f":r.~\,<br />
\" I )<br />
~~,,>y<br />
ECKERMANNITE<br />
PIEMONTITE<br />
Fig. 1.<br />
Optical orientation of blandfordite, manganarfvedsonite, eckermannite<br />
and piemontite.<br />
Table 1. The chemical composition and the unit cell of blanfordite from Goldongri,<br />
India. Chemical analysis by Paavo Väänänen, M. Sc., of the Geological Survey of<br />
Finland.<br />
wt % I cation<br />
%<br />
Unit cell content<br />
Si0 2<br />
. .... ,- 52.86 50.3 Si ... . . . 7.97 atoms<br />
AI 2 0 S<br />
.... .. 1.43 1.6 Al .. ....<br />
0")<br />
The unit ce11:<br />
Fe 2 0 S<br />
...... 27.61 19.7 FeS + . ... o. 3.13<br />
a<br />
3.61<br />
= 9.64 A<br />
FeO ..... . - b = 8.78 ,)<br />
Mn 2 0:; . . . . .. 1.91 1.4 Mns + , . .. ,. 0.22 C = 5.28 ,)<br />
MnO ... . . . 0.09 0.1 Mn2 + . . . . ..<br />
ß = 106 0 57'<br />
MgO ..... . 1. 47 2.1 Mg ... , , . 0.34 0.44 Vo = 427.5 A3<br />
Ti0 2 ..... . 0.75 0.5 Ti •••• o • 0.09 Z =4<br />
°"1<br />
CaO .. ... . 1.57 1.6 Ca .... .. 0.25 Space group C 2/c<br />
Na 2 0 ... . . . 11.94 21.9 Na •••• o • 3.52 3.80 D = 3.516<br />
K 2 0 ..... . 0.15 0.2 K ..... . 0.03<br />
I Aegirine 80 mol. 'X o<br />
H 2<br />
0 + .... .. 0.07 0.4 OH •••• o • 0.09 Jadeite 10 » ')<br />
H 2 0 ..... . 0.02<br />
.. , ... 23.80 Johansenite 6 ,) ,)<br />
CO 2<br />
, .. ... n. d. l Enstatite 4 » ,)<br />
PbO .... . . n. d .<br />
CuO ... , .. n. d .<br />
P 2 O., .... .. 0.04 0.1<br />
99.91 I 100.0<br />
°
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