Chap. III.] 
braunIte. 
53 
mineral in India was first recognized by Dr. A. J. Scott in 1852 ^, who 
analysed two specimens said to have come from Vizianagram and 
Bimlipatam, respectively. As manganese-ores are not known to exist at 
either of these towns, the probability is that the specimens were obtained 
from the manganiferous area of the district in which these two places 
are situated. From the account given of the characters of the ores 
examined it is evident that they consisted of mixtures of braunite and 
psilomelane. The analyses of these two specimens are given in the 
paper cited, and Scott remarks with regard to the Vizianagram ore that 
its analysis agrees most nearly with that of Damour's Marcellin, an 
impure braunite from St. Marcel in Piedmont. Two years later Mr. 
Marcadieu recorded the discovery near Dharmsala in the Punjab (see 
page 1156) of a mineral that 'approaches by its composition and 
crystalline form to marcelline '. The crystals he describes as octahedral 
with a square basis. ^ Since then it has been found to occur in 
great abundance in various parts of India. I do not intend to give 
here a detailed account of all the occurrences of this ore, but will only 
refer to the most interesting and important of them. An account 
of all that was knowTj about Indian braunite up to the year 1887 will, 
however, be found on pages 55 to 57 of Mallet's ' Mineralogy '. 
As far as my own experience goes braunite is found in India only in 
association with the manganese-ore deposits that 
Occurrence. occur in the Archaean rocks. And, as is described 
in the chapters dealing with the geology of these 
deposits, there are two chief groups of these deposits. The braunite that 
occurs in the deposits formed by the chemical alteration of the rocks 
of the Jjodurite series in Vizagapatam has, if my view of the origin of 
the ores of this area be correct, been formed during the chemical changes 
by which the manganese-ores were derived from the manganese-sili- 
cate minerals. In these deposits, however, braunite is not nearly so 
abundant as in the deposits occurring in the rocks of Dharwar age in the 
Central Provinces, Central India, and Narukot, i.e., in association 
with the gondite series. In these latter deposits I suppose that a portion 
of the manganese-ores has been formed direct by the metamorphism of 
the original manganiferous sediments, whilst another portion of the ores 
has been formed by the chemical alteration of the manganese silicates 
that were formed by the metamorphism of the more impure of the 
1 Edin. New Phil. J our., nil, pp. 277-279. 
2 Selections, PubJic Correspondence, Punjab Administration, II, No.vii, p. 4. 
