118 
MAXG^XESE DEPOSITS OF IXDIA : MINERALOGY. [ ParT I : 
it has in all probability replaced. Wad also occurs in the lithomargic 
rocks associated with the manganese-ore deposits at Ramandrug. In 
Mysore there is also a great abundance of wad associated with the 
manganese-ore deposits in each ol the tour districts of Chitaldi'ug, 
Kadur, Shimoga, and Tumkur. It usually occurs associated with 
lithomarges and ochres in the soft altered rocks underlpng the man- 
ganese-ore deposits. It is usually very light in weight, and, as a rule, 
is very fine-grained and compact, with a tendency to possess the 
structure of compact lithomaige. In colour it varies from almost 
pure black through deep brownish black to the brown of an ochre, 
there being a passage from one to the other, corresponding no doubt 
to changes in the relative amounts of manganese and iron. The streak 
is similar to that of the Sandur wad. Passages from wad to psiiomelane 
can often be seen in the Mysore deposits. Another example of what may 
be regarded as wad is the specimen , of which the analysis is given on page 
114, from Sontulai in the Hoshangabad district, Central Provinces. Other 
examples are to be found amongst the lateritic ores in most parts of India. 
In many of the most compact ores of the Nagpur-Balaghat area, 
Central Provinces, cavities or cracks are often found containing a small 
quantity of a deep brown velvety powder, which is also probably to be 
included under the term wad. 
The following two analyses of wads from the Vizagapatam district 
were carried out by Messrs. J. &H. S. Pattinson 
omiio.s.tion. Newcastle-on-Tyne, on specimens carefidly 
picked by myself so as to be as far as possible homogeneous. Omng to 
the soft and crumbly nature of the specimens it was not possible to 
take their specific gravity. 
