Chap. III. ] 
VREDENBURGITK. 
43 
chocolate. Its hardness is about 6 "5. The most interesting feature of the 
mineral, however, is its magnetism, for it seems to be just as strongly 
magnetic as ordinary magnetite ; and indeed, any one picking up a piece 
of it and testing it with a magnet would say at once that it was mag- 
netite. That this would be incorrect is shown by the fact that the min- 
eral contains a high percentage of manganese ; in fact, about twice as 
much of this element as of iron. The mineral is, moreover, distinctly 
polar, and pieces can be broken off, one end of which will attract one 
pole of a balanced magnetic needle and repel the other. The coarsely 
crystallized Garividi specimen is more suitable for this test than the more 
finely crystalline ore from Beldongri, the latter being of the nature of 
an aggregate in which the polarity of one individual may neutralize 
that of another. 
The Beldongri specimen was found as a thin band, one inch in 
thickness, intercalated with the other ores in the south-east corner of the 
quarry, at the point D in Plate 37. This ore is moderately coarsely 
crystalline, as compared with the usual manganese-ores of this part 
of India, the individual grains averaging to J inch across. This crystal- 
line aggregate is very compact, and in parts the magnetic mineral tends 
to get mixed with a little psilomelane. A piece, apparenth^ free from this 
latter impurity and having a specific gravity of 4 "74, was selected 
for analysis, the latter being carried out at the Imperial Institute. The 
other specimen was obtained from amongst the heaps of ore from the 
Garividi deposit, stacked ready for despatch at the station of the same 
name. In contrast to the Beldongri specimen this is very coarsely 
crystalline, a piece about three inches in length consisting of only three 
individuals interlocldng one with the other in a sort of poikilitic way. One 
of these individuals is two inches long. The Garividi specimen, more- 
over, does not contain any other admixed mineral. The piece of it 
chosen for analysis had a specific gravity of 4 "84, which is somewhat 
higher than that of the Beldongri specimen. This may mean that there 
was a little admixed psilomelane in the Beldongri ore, although the way 
in which the analysis works out to a definite formula does not support 
this supposition. The shght differences in specific gravity may be due 
to slight differences in the impurities that each 
Chemical composition. r , ■ i ii • 
oi the specunens probably contam ( see the 
analyses on the )iext three pages ). The Garividi specimen was 
analysed by Messrs. J. & H. S. Pattinson of Newcastle-on- 
Tyne. 
