196 
MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ PaRT I 
basal section showed the following pleochroism, assuming the two axes 
lying in this plane to be b and t : — 
c = greenish brown to pale brownish green or sage-green, 
b = red-brown to raw sienna. 
I have called this mineral manganchlorite ? because the flakes or 
laminae are not elastic. The pleochroism shows that this cannot 
be the same as the Swedish manganchlorite and it may be that it is 
really an altered mica ; but in this case it could not be regarded 
as manganophyllite, which it resembles in its colour, because of its high 
optic axial angle. If an altered mica, it cannot be caswellite, both on 
account of its pleochroism and because it looks very different to a speci- 
men of caswellite in the Geological Survey collection. Hence if a mica 
it must be a new variety. Provisionally, therefore, I shall call it man- 
ganchlorite ?, and will so refer to it whenever I have occasion 
to mention this mineral in the descriptive part of this Memoir. This 
will thus serve to distinguish the mineral from all the other micaceous 
minerals found in the manganese-ore deposits ; for these are all true 
micas, as is shown by the elasticity of their flakes. 
Brown Micas (Manganophyllite ? 
Micas showing some tint of rich brown, bronze, or deep orange, 
are fairly often found in the micaceous schists, of which a list is given on 
page 333, associated with the rocks of the gondite series. The following 
is a list of the places at which such micas have been found : — 
Bombay : — Jothvad. 
Central India : — Kajlidongri. 
Central Provinces — 
Bhandara district : — Sitapathiir. 
Xagpur district : — Ghogara, Junawani, Kacliarwahi, Pali, Ramdongri, 
Satak. 
Some of these micas are uniaxial and some of them biaxial, some- 
times strongly so. It is possible that some of them may be manga- 
nophyllite, but it is almost certain that there are two or more species 
amongst them. T v/ill notice three of the occurrences only. 
Jothvad : — Many of the rocks I collected at this place contain brown 
micas. Although some of these are uniaxial and some biaxial, there 
does not seem to be a sufficient difference between their tints to enable 
one to tell without obtaining an interference figure which micas are uni- 
axial and which biaxial. The pleochroism is : — 
-,t = orange, pinkish yellow, and orange-pink, 
I) and C = deep orange, reddish orange, and red-brown. 
