6t6 
MANGANESE DEPOSITS DF INDIA : DESCRIPTIVE. [PaP.T IV : 
This rock, which was named ' calderite ' by H. Piddington, was analysed 
by Mr. Tween and found to be a lime-iron garnet containing traces of 
mangauese.l One specimen, however, from Katkamsandi, 12 miles 
north-west of Hazaribagh, of dark brown or black colour and resinous 
lustre, with a specific gravity of 3*65, was analysed by Piddington^ and 
found to be a manganese-iron garnet containing 21 per cent, of MnO. 
On account of the ratio of protoxide to peroxide being quite wrong for a 
garnet, Mr. F. R. Mallet^ throws doubt on the accuracy of this analysis, 
not thinking it probable that ' calderite ' varies to such an extent as the 
analyses of Tweeu and Piddington indicate. In support of the fact in- 
dicated by Piddington's analysis that some varieties of calderite are very 
manganiferous, may be mentioned a specimen recently received at the 
(geological Survey Office from Mr. J. W. Bollard of Kharagdiha. It 
was coiiected by Lim at Sirsia, 5| miles S. E. of this place and is a massive 
rock composed of a mixture of a resin-brown garnet (presumably calde- 
rite) and a bright green pyroxene (coccolite of Mallet) with specks and 
veinlets of galena probably introduced by metasomatic replacement. 
The garnet reacts strongly for manganese and the pyroxene feebly so, 
and under the microscope the pyroxene is seen to be of a pale bluish 
colour, probably due to its manganiferous character. For further re- 
marks on calderite see pages 182 to 185. 
Kalahandi State. 
Along with iron-ore on a hill near Olatura, Dr. T. L. Walker 4 found 
Some A'ery manganiferous varieties containing up to 41 "03 per cent, 
manganese. Mammillary concretions containing cobalt were found. 
An analysis of one specimen gave the following result : — 
Insoluble in HCl. 29-41 
Mn calculaterl as MnO 43-30 
BaO 
■ FeoOa 7-84 
? CoO 0-82 
Loss on ignition ....... 10-46 
Constituents of the soluble portion not determined . 3-66 
100-00 
Metallic ffianganese 
27-37 
1 F R. Mallet, Mineralogy, p. 89, (1887). 
2 Jour. As. Soc. Beng., XIX, p. 147, (1850). 
8 Mineralogy, p. 90. 
i 31 em. Geol. Surv. Ind., XXXIll, pt. 3, p. 20, (1902). 
