126 
MANGANESE DEPOSITS OF INDIA : MINERALOGY. [ PaRT I 
clinic, with a small angle of extinction. The crystals noted below show three 
forms, the prism, clino-pinacoid and clino-domc, and sometimes exhibit baaal 
parting planes best seen in thin sections under the microscope. In sections at 
right angles to the acute bisecrix a figure can be obtained, but points of emer- 
gence of the optic axes lie outside the field of view of the microscope. The 
specific gravity (as determined with some minute fragments and Sonstadt's 
solution) is 3-15. Before the blowpipe the mineral fuses easily to a black bead, 
gives a marked sodium flame and with fluxes gives indications of small quantities 
of manganese and iron. It occurs partly as a pyroxene-braunite-rock with inter- 
titial apatite, and partly in aggregates and scattered crystals up to an inch long 
in a rather coarsely crystalline albite-rock. I propose to call this mineral blan- 
fordite, after the late Dr. W. T. Blanf ord.' . j 
Since this was written I have been able to pay a second visit to this 
locality and obtain a further supply of the mineral. I have at present 
little to add to the above account, except that in some of the thin sections 
of the rocks containing blanfordite I have found an amphibole of some- 
what similar pleochroism that is likely at first to be confounded with the 
pyroxene unless the conniderably lower index of refraction of the amphi- 
bole be noticed, or a section be hit upon that shows the characteristic 
cleavages of the amphibole group (see juddite). Moreover, the albite- 
rock mentioned above frequently contains microcline and sometimes a 
Crystallogra p h i c little quartz. Tn figures 11 and 12 illustrations 
characters. are given of two crystals of this mineral. 
Figure 11, showing the forms m (110), h (010), and e (Oil), represents the 
common habit of the mineral, the crystals of this habit ranging 
J Fig. 11— Blanfordite. Fig. 12— Blanfordite. 
from perhaps^ inch in diameter up to the size figured. Figure 12, 
