48 
MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ PaRT I t 
If in each of the analyses the iron be supposed to be present in the form 
of Fe304 and the manganese in the form of Mn203, then the amounts of 
these oxides work out as follows : — 
MU2O3 
re304 
8iibtrac( 0 assumed . 
Beldongri. 
Garividi. 
64-08 
65-51 
27-89 
30-25 
91-97 
95-76 
1-21 
1-00 
90-76 
94-76 
With this arrangement the formula works out as corresponding in 
both cases very closely to 10Mn2O3.3Fe3O4. Since, however, the 
error in the oxygen is on this interpretation so large, it would be better 
to suppose that the manganese is not all in the form of Mn203, but that 
a portion of it is in the R3O4 group isomorphously replacing a portion 
of the iron. On this supposition and using the oxygen, manganese, 
and iron, as actually determined, as the basis of calculation, the 
composition works out as follows : — 
Beldongri. Garividi. 
Mn203 , . . . 28-23 35-89 
MnsOi .... 34-64 28-62 
YezOi .... 27-89 30-25 
90-76 94-76 
The molecular proportions of the three oxides then work out as follows : — 
Beldongri. 
Mn203 
Mn304 
Fe304 
. - -1787 
. = 1513") 
[ -2715 
. = -1202) 
Garividi. 
= 2x 
= 3x 
•0893 
-0905 
Mn203 
Mn304 
Fe304 
. = -2271 
. = -1249T 
[ -2553 
. = -1304 ) 
= 7 X 
= 8x 
■0324 
•0319 
These correspond respectively to the formulae — 
Beldongri . . . 2Mn203-3(Mn.Fe);i04 
Garividi . . . 7Mn203.8(Mn,Fe)304 
We have thus arrived at the following alternative formula) : — 
Beldongri. Garividi. 
3Mn304.2Fe203 | 3Mn:i04.2Fe203 
10Mn2O3.3Fe3O4 | 10Mn2O3.3Fe3O4 
2Mn203.3(Mn,Fe)304 ' 7Mn203.8(Mn,Fe)30t 
