1124 MANGANESE DEPOSITS OF INDIA : DESCRIPTIVE. [ PaRT IV : 
the outer shell of the pisolites being limonitic. In places this form of 
the rock tends to give way to the manganiferons form again. Higher 
up this rock gives place to cavernous limonitic rock, sometimes more 
compact, and in places passing into psilomelane, the cavernous, psilo- 
melanic, limonite rock extending right to the top of the hill. The 
various varieties of rock described above would often, if seen in detached 
pieces, be called ' laterite. ' And indeed it seems as if this lateritoid, 
and consequently all the lateritoid containing manganese-ore that I 
have seen in Mysore, is really a form of true laterite, formed by the 
surface alteration and metasomatic replacement of quartzites, phyllites, 
and other Dharwar rocks. I shall still call it lateritoid, however, to 
distinguish it from the form of laterite that is found in horizontal 
sheets. 
Amongst the ochres and wads there is a dark brown rock of light 
weight, cutting like soap, that dissolves entirely 
Manganiferous oohre. • i i i, • -i t i • 
m hydrochloric acid, it must be a mangani- 
ferous ochre intermediate in composition between ochre and wad. 
The ores are partly psilomelane, often spoilt by limonite, or remains 
, , of quartzite or argillaceous rock, and con- 
Ntiturc of tnc ores 
taining either botryoidal psilomelane or pyro- 
lusite needles in cavities ; and partly pyrolusite, usually fine-grained, 
with either quartz or pyrolusite crystals in cavities, and also showing 
remains of quartzite. The ores hence tend to be high in silica. 
2. Dod Kittadhalli. 
Specimens of brown hematite from this place assayed 1-46 to 3-54 y!^ 
MnO,^ whilst some black iron sand showed M0% MnO. 
3. Madadkere. 
This jilace is some 4 miles to the south of Dod Kittadhalli. Ac- 
cording to Mr. V. S. Sambasiva lyer^ a dark brownish black soft 
earthy ore of manganese, soiling the fingers and yielding about 44^ of 
MnO, corresponding to 34 % Mn, with less than 1 ^ of insoluble residue, 
occurs intimately associated with hematitic quartzite and earthy and 
ferruginous limestone in the long low hills east of Madadkere. The 
lOp. II, pp. 42, 43, (1898-99). 
2 Op, cit., IV, pp. 160, 101, (1902-03). 
