Cn\r. XXXVI.] 
NAcruu : 
MANEGAON. 
945 
Hence we may regard the ore-bands as being immediately enclosed in 
mica-schists and these, in their turn, in quartzites. 
Although the main ore-band is so thick, yet at many points 
Ciim-ictcr of ilic oic only a comparatively small proportion of it consists 
biuuls. of merchantable manganese-ore. Apart from the 
bands of quartzite and soft micaceous sandstone-like quartzite that are 
found interbanded with the manganiferous rocks, a very considerable 
proportion of the latter is either quite fresh or only partly altered to 
manganese-ore. Among these manganiferous rocks there is a very large 
quantity of rhodonite-bearing rocks. In places the rock is entirely 
composed of this mineral, then being of a beautiful rose-pink, often veined 
and mottled with black, owing to partial alteration. Sometimes 
the rock contains scattered orange spessartite, and at others forms a very 
tough massive, rhodonite-spessartite-rock, often partly altered to manga- 
nese-ore. There are also many varieties of spessartite-rock and spessar- 
tite-quartz-rock (gondite). Many of the varieties of rhodonite-rock, if 
they could be obtained in sufficiently large pieces, would make a 
handsome ornamental stone. Similar rhodonite- and spessartite-bearing 
rocks are also found in the subsidiary ore-band. 
There are several varieties of manganese-ore found in this deposit. 
One is a finely crystalline ore of magnetic braunite, 
of Uio")it"'"' varying from friable to hard, according as the ce- 
ment is soft black oxide, or hard grey psilomelane. 
Another variety is hard psilomelane, with only a small percentage of 
scattered braunite grains. A third is very dirty and shows rather large 
braunite grains, partly in a sooty matrix and partly in a psilomelane 
matrix. The ore often contains remains of orange garnet or blackened 
rhodonite. Sample No. 34, representing some 1,900 tons of ore, was 
taken from the ore-stacks and consisted of all the above varieties, several 
pieces showing remains of garnet and some of quartz, and it looked as 
if the quality of the ore stacked could easily be raised by more careful 
cleaning of the ore. The analysis carried out at the Imperial Institute 
shows : — 
Sample No. 34. 
Manganese peroxide ....... 49 -45 
Manganese protoxide . . . . . . . 23-04 
Ferric oxide . . . . . . . . .14-06 
Silica (combined) ........ 2-61 
Silica (free) 2-70 
Phosphoric oxide ........ 0*21 
Moisture at 100°C 0-35 
This is equivalent to : — 
Manjjanese . . . . . . , . . 49-15 
Iron ... 10-26 
Silica 5-31 
Phosphorus . . ...... 0-09 
Moisturu . ...... 0-35 
