188 
MANGANESE DEPOSITS OK INDIA : MINERALOGY. [ PaRT 1 
Other epidotes that have pleochroisra schemes similar to those of 
„„ ,. , , . piedmontite are thulite and withamite. Thulite is 
ihuhte and uithamite. . . 
a variety or the orthorhombic epidote, zoisite, and 
does not contain manganese. In fact no orthorhombic manganese-epi- 
dote seems to be known. Withamite is a variety of ordinary epidote 
containing a very small percentage of manganese. It is found at Glen- 
coe in Scotland and an analysis by Heddle showed only 0'14% of MnO. 
The pleochroism schemes of thulite and withamite are shown below : — 
Thulite. ^Vithamite. 
a = light rose. a = lemon-yellow, 
b = deep rose. b — light rose. 
C = yellow. C = Strang r:se. 
It will be seen from this that the pleochroism tints of these two 
minerals are similar, except that the colours for the a and c axes of 
withamite, which corresponds in pleochroism to piedmontite, are 
interchanged in thulite. 
It is obvious from what has been written above that it must be a 
matter of considerable difficulty to settle, merely 
Distinction between from the examination of thin sections under the 
the different mangani- . i ,i ji • i • r ,^ 
ferous epidotes. microscope, whether the nuneral is one or the 
epidotes, withamite or thulite, containing little or 
no manganese, or whether it is one of the more manganiferous ones, 
piedmontite or mangan-epidote. But a test for manganese, made on a 
small carefully picked chip of the mineral will be sufficient to settle 
this point. For if a decided reaction for manganese be obtained the 
mineral cannot be thulite or withamite, but must be either piedmontite 
or mangan-epidote. It is more likely to be piedmontite, because this 
is much commoner than mangan-epidote, but as noticed above the only 
way to determine this point is to determine the sign of the mineral, a 
positive sign characterizing piedmontite and a negative mangan-epidote. 
The investigation of the Indian manganese-ore deposits has led 
to the discovery of this mineral at several locali- 
Occurrence in India. • ji . i i ■ a i 
ties in the Archaean schists oi the areas where 
the rocks of the gondite series are found. The following is a list of 
localities : — 
Central Provinces — 
Nagpur di-trict: — Ghogaia, Junapaiii, Junawani, Maharkund, Mohugaon, 
Pali, Rajkota. 
Central India — 
Jhabua State :— Kajlidongri. 
Bombay — 
Nanikot State : — Jothvad. 
