Chap. V.] 
WINCH ITE. 
149 
ish white in hand-specimens and colourless under the microscope. Con- 
sidering the fact that all the constituents of the rock in which it occurs 
are non-manganiferous except the piedmontite, it is not at all improbable 
that this amphibole is also non-manganiferous. 
At KajUdongri I found two occurrences of amphiboles, leaving the 
winchite entirely out of consideration. One of 
Kajlidoagn. 
these is in a banded rock composed of yellow 
pyroxene, yellow amphibole, and quartz, with a little felspar. The 
pyroxene is that noticed on page 136. The amphibole is in irregular 
prismatic individuals as seen in the microscope section, and shows the 
following pleochroism : — 
a=yellow with a brownish or orange tinge, 
b=pale straw, sometimes with a greenish tinge. 
The crystals are of low birefringence, sho\ving under polarized light a very 
patchy appearance. This is due to zoning, the outer portions of 
the crystals ha\ing a larger value for the angle a a c than the 
inner, with a more or less gradual change from one to the other. One 
example showed patches with an extinction angle of 22|^, in a main 
portion with extinction angles of io° to ol^ ; whilst another showed a 
change from 10° inside to 37^ outside. In this character the mineral 
very closely simulates winchite. The other occurrence is in a rock 
composed of crimson mica, talc, apatite, and the amphibole. The latter 
was not evident in the hand-specimen, and under the microscope practi- 
cally colourless, so that it might be either tremoUte or a very pale variety 
of winchite. 
From a consideration of the foregoing it seems that in general aspect 
the amphibole of the Central Provinces bears considerable resemblance 
to dannemorite. 
Winchite. 
Of this mineral, originally foimd by Mr. H. J. Winch of Meghnagar at 
the manganese mine, Kajlidongri, Jhabua State, Central India, I gave a 
preliminary description in the i?ee. Geo^. Surv. /«(/., XXXI, pp. 235, 236. 
(1904:) ; and in the Trans. Min. Geol. Inst. Ind., I, p. 79, (1906), announced 
the name of it as ivinchite, after the original discoverer. In February 
1905 I was able to \"isit KajUdongri and collect considerable quantities 
of the mineral, with the rocks in which it occurs. As the result of a 
study of a large number of thin sections under the microscope I am 
