776 
MANGANESE DEPOSITS OF INDIA : DESCRIPTIVE. [pAKT IV . 
grey finely crystalline braunite with fairly numerous black spots about 
^ inch in diameter. The former variety of ore characterizes hillocks 
Nos. 1 to 3, while hillock No. 4 shows both varieties. 
In December 1907 I saw one block of quarried ore consisting of a 
mixture of hollandite, braunite, and psilomelane, with a squarish patch 
of bronze-tinted ore, probably the same as sitaparite found at Sitapar. 
The ores will everywhere need careful cleaning, as they contain 
in various places spessartite, quartz, chalcedony, magnetite, albite, and 
pink felspar. 
I picked out for analysis a piece of ore that seemed to be composed 
entirely of finely granular braunite. In places it tended to be slightly 
more coarsely crystalline. The specimen was analysed at the Imperial 
Institute with the following result : — 
Specimen No. 797 {17--1). 
Manganese peroxide 
Manganese protoxide 
Ferric oxide . 
Alumina 
Baryta . 
Lime 
Magnesia 
Combined silica 
Free silica 
Phosphoric oxide . 
Arsenic oxide 
Combined water 
Moisture at 100°C. 
Carbon dioxide 
42 -80 
35-45 
fi-70 
0-26 
0- 00 
1- 31 
315 
8-75 
0-00 
003 
0-002 
0-91 
0-09 
0-06 
99-572 
Manganese 
Iron 
Silica (total) 
Phosphorus 
.54-60 
4-69 
8-75 
0-013 
Specific gravity 
4-71 
At first I attempted to re-arrange this analysis in terms of its minera- 
logical composition on the assumption that it contained braunite of the 
formula 3Mn203. MnSiOs, with a small amount of interstitial psilomelane. 
The analysis was found not to correspond to any such mixture and it 
was found necessary to assume that the formula of the braunite present 
