858 
MANGANESE DEPOSITS OF INDIA : DESCRIPTIVE. [PaRT IV: 
schists. But, on the other side of the nala there occurs almost at once 
another, though very small, lenticle of ore forming hillock No. 13. The 
lenticle, which runs E. 10° S., is exposed for a length of about 150 yards 
and may be 30 yards across ; at its west end it runs almost to the very 
bank of the nala in which the schists are seen. The ' country ' on the 
north side is grey gneiss, which, together v^ith schists and quartzites, 
separates this lenticle from the deposit of hill 5. The ore itself is mostly 
not of much value. 
This is the hillock to the north of hill 5. The manganiferous rocks 
here consist of manganese-ore, and partly altered spessartite-rock and 
jj.jj y spessartite-rhodonite-rock with quartz. There is a 
certain amount of merchantable ore, but pro- 
bably net enough to repay the cost of extraction. The associated rocks 
are pinkish quartzites, micaceous schists, and tourmaline-gneiss and 
granite. 
The ore of these deposits is largely the usual fine-grained hard grey 
Nature and quality of compact mixture of bramiite and psilomelane ; but 
the ores. " there is a fair proportion, mainly in hill 5, of coarsely 
crystalline ore, showing facets up to J or | inch across, nearly all the ore 
then being braunite. It seems possible that the fine-grained compact 
ore has been formed from spessartite-rock and the facetted ore from 
rhodonite-rock. 
I took four samples, the analyses of which carried out at the Imperial 
Institute are shown in the following table : — 
Analyses of Rdmdongri ores. 
Sample number 
3 
4 
5 
Manganese peroxide . 
48- 
25 
51 
75 
51- 
33 
46 
48 
Manganese protoxide . 
28- 
10 
27 
48 
26- 
79 
28 
25 
Ferric oxide .... 
11- 
81 
8 
46 
8 
58 
10 
00 
Silica (combined) 
5- 
19 
5 
69 
6 
15 
6 
50 
Silica (free) .... 
0- 
28 
0 
39 
0 
38 
1 
14 
Phosphoric oxide 
0- 
19 
0 
22 
0 
13 
0 
35 
Moisture at 100° C. . 
0 
37 
0 
38 
0 
36 
0 
63 
Manganese .... 
53 
34 
54 
07 
53 
17 
51 
31 
Iron ..... 
8 
27 
5 
92 
6 
01 
7 
•00 
Silica' .... 
5 
47 
•08 
6 
53 
7 
•64 
Phosph'-nis .... 
0 
12 
0 
08 
0 
10 
0 
•06 
