CHAPTER V. 
mm KRALOGY— continued. 
Silicates -Pyroxenes and Amphiboles. 
ftlanfordite— Mauganhedenbergite— Schefterite (?) & urbauite (?)— Pyroxenes of 
Vizagapatam — Colourless pyroxenes — JefTersonite — Rhodonite — Manganese amphiboles 
— Dannemorite ( ?)— Winchite— J uddite. 
Manganese-bearing pyroxenes. 
Amongst the manganese-bearing rocks in the Archaean areas of Vizag- 
apatam, the Central Provinces, Jhabua, and Narukot, pyroxenes contain- 
ing a certain quantity of manganese are fairly common. There see ns to 
be a considerable variety of such pyroxenes, owing no doubt to variations 
It) the amounts of manganese and other constituents present : rhodonite is 
the species containing the most manganese, being manganese metasilicate ; 
whilst most of the other varieties probably contain but very small quanti- 
ties of manganese. Several of these are probably varieties new to science ; 
but, in most cases, they have not yet been closely examined, except in so 
far as is necessary in the course of the microscopic examination of thin 
slices of the rocks in which they occur. Nevertheless, I will give below 
the little I have determined with regard to these pyroxenes. 
Blanfordite. 
The name of this variety has already been announced in a paper read 
The Kacharwahi occur- before the Mining and Gological Institute of 
ronce. India, and 1 cannot do better than quote here 
what was published in the Transactions of this Instituted The typical 
mineral was found in the Karharwahi quarry, Nagpur district. The 
account of this mineral given in the above-cited publication is as follows :- 
' It is notable for its stri ;ing and beautiful pleochroism, which even in thin 
sections is — 
a=rose-pink, 
h=bluish lilac, 
f=sky-blue. 
'In thick seclioas the a and b axis colours are deep carmine and very rich 
sky-blue respectively. When fresh, the pyroxene is 
Original account. . ^ • .^-^ ■ 
deep crimson as seen m hand specimens, but it is 
often altered so as to be chocolate-brown in colour. The mineral is mono- 
» Vol. I, p. 78, (1906). 
