Chap. VTT. ] mangiankse-micas and chlorites. 
195 
Tlie mineral is found at the Harstig mine near Pajsberg, Sweden, in 
association with manganopliyllitej which it resembles, but from which 
it is distinguished by a lighter reddish colour. The double refraction 
and pleochroism are weak, whilst the mineral is distinctly biaxial. Cer- 
tain characters point to the possibility of this chlorite being triclinic. 
Indian Mang:anese-ujicas and Chlorites. 
Associated with the Indian manganese-ore deposits of the gondite 
series there is a considerable variety of micaceous minerals ; these are 
in most cases true micas, but occasionally may be either chlorites or 
altered micas. Although micas are comparatively common in some 
of these deposits, it is usually in the deposits of somewhat exceptional 
character, such as those where micaceous schists have been developed. 
The mineral is very rare in the true gonditic rocks. From these mica- 
ceous minerals we can first separate the variety that may be either man- 
ganchlorite or an altered mica. This mineral 
is found only in the Central Provinces, usually 
intimately associated with the manganese-ores ; it has not yet been 
found in the rocks of the gondite series associated with the ores. 
The localities for this mineral are the following : — 
Kalaghat district : — Ramrama. 
Bhandara district : — Kosumbah, Sukli. 
Chhindwara district : — Kachi Dhana, Sitapar, 
The mineral occurs in small books in the midst of the manganese-ore 
and almost always seems to be suffering alteration with the production 
of manganese-ore, probably by replacement. In colour it is bronze- 
to copper- coloured, and gives a bronze-coloured streak. 
A flake of the Kachi Dhana mineral was found under the microscope 
to give a biaxial interference figures, to be rich deep brown in colour, 
and to contain star-like inclusions, probably indicating the development 
of some secondary manganese- ore. The flakes were flexible but not 
elastic. A flake, examined to see that it was free from these inclusions, 
was foimd on fusion with the usual fluxes to give a distinct reaction for 
manganese. At Sitapar the mineral occurs in a rock containing four 
manganese-ores and an arsenate, as noticed on page 786. Some of the 
plates of the micaceous mineral from this locality are a greasy brown in 
appearance, whilst others are of a bronzy, almost copper, brown. The 
optic axial angle was found to be exactly the same as that of a flake 
of muscovite of which the optic axial angle was known to be 70°. A 
I o 2 
