1112 MANGANESE DEPOSITS OF INDIA : DBSCRIPTIVE. [ PaRT IV 
minate under the microscope, as they all show extinctions up to 45*^ 
referred to prismatic cleavages. In somewhat thicker sections, how- 
ever, the rhodonite remains colourless, whilst the brown pyroxene 
assumes a pale yellowish or brownish tint and the green pyroxene a 
pale yellowish green tint. As pyroxenes make up the main bulk of these 
rocks they can be best designated manganese-fyroxenites. One variety 
composed almost entirely of brownish green pyroxene contains little 
prisms of pale greenish apatite up to \ inch long. 
The loose blocks and pebbles of manganiferous rocks found on the 
hill slopes and in the stream-bed were doubtless, at least partly, derived 
from the band noticed above. But some cf them may have been derived 
from another band of these rocks situated further up the valley and as 
yet undiscovered. The majority of these boulders was composed of 
the various varieties of manganese -pyroxenites like those mentioned 
above. A few of them, however, showed other minerals in addition. 
Thus one block showed a layer of quartz con- 
ite^h^doalte^qu^t^^ taining scattered deep orange-coloured spandite 
grains and a few scattered graphite scales. 
This layer rested on one composed of a rather fine-grained aggregate of 
quartz, spandite, and rhodonite. Under the microscope this rock was 
seen to contain sphene also, and a few grains of a mineral suggesting 
P3rrrhotite, besides fairly abundant apatite. 
Another boulder was an ochreous very graphitic rock, seen under the 
microscope to contain abundance of apatite and 
lock'witttuanganL^i-'or?" P^^® yellowish garnet in a dark matrix com- 
posed ajjparently of graphite, brown iron-ores, 
and black manganese-ore, of which the last-named is evidently replac- 
ing both garnet and apatite. 
Another boulder was composed of the garnet in a matrix of manga- 
nese-ore and probably represents original spandite-rock. 
Where the ore-band crops out, exposures of both the overlying and 
™i , underlying rocks can also be found. The under- 
iw calcareous gneisses, . 
lying rock is always some variety of the 
calcareous gneisses. At one place this rock was a wcUastonite-gneiss, 
containing subordmaie pyroxene, plagioclase, sphene; at another it 
was a ecapolitic gneiss composed of seapolite and green pyroxene with 
