Chap. III.] 
SITAPARITE. 
51 
any important effect on the formula. Their total amount was, however, 
not so small, being about 9 per cent, in the Beldongri specimen and 5 per 
cent, in the Garividi specimen. 
In the present case one of the constituents other than oxides of man- 
ganese and iron is present in sufficient quantity for it to be necessary 
to take it into account in calculating the formula. This is the lime ; 
and in investigating the significance of this constituent in the for- 
mula I have grouped with it the oxides of barium and magnesium. 
Below I give the figures for the molecular ratio of each constituent : — 
Mn02 ^r^=r. 0 -4230 =10 x "0423 
MnO =_26-89 ^ Q.gyg^ = 9 x 0421 
71 
Fe203 = — = 0 1725 = 4 x 0431 
KiO 
CaO = = 0-1096 "1 
or, , 
I 
M^O = = 00253 !- = 0-1355 = 3 x -0-:52 
40 -36 I 
I 
BaO = = OOOOG J 
153-4 
SiOo =-. ^ 0 0194 = t X 0485 
00 -4 
In the last line I have also given the molecular ratio for the silica to 
show that it is present in too small a quantity to be taken into account 
in working out the formula of the mineial. It will be seen, however, 
that the CaO, MgO and BaO taken together are molecularly nearly as 
important as the ferric oxide. According to the above the formula 
ij as follows : — 
10MnO2 . 9MnO. 4Fe203 . 3(Ca,Mg,Ba) 0. 
Leaving out the MgO and BaO and grouping together the oxides of 
manganese this can be stated more simply as follows : — 
9Mn203 . 4Fe203 . Mn02.3CaO . 
