M.228 - Manganese mines in Goa (Portuguese India)

Goa manganese is not as widespread as in the central provinces of India, and in particular as in the mines around Madras. It does, however, occur in fairly large deposits, which are very easy to extract. Often, however, apparently excellent showings are scattered in profusion on the ground, but are not followed by any serious results when work begins...
No more than a third of the mines granted by the Portuguese government are of limited value, and only a tenth are excellent. 
The 2 main reasons why some mines are unworkable are, on the one hand, the presence of silicate in excess of 10% and, on the other, the fact that manganese, although in large quantities, is so intimately mixed with laterite that its separation and sale are no longer profitable.
Laterite is a kind of red or yellow argillaceous sandstone that is found all over Goa and is a peculiarity of India and Ceylon. Sometimes, this laterite is deposited on top of a good quality metal bed, but the work required to remove it and then mine the manganese would be too costly at current selling prices. The main value of the Goa mines lies in their location, from the mining point of view. They are all located a short distance from the port of Mormugao, and many can use canals or rivers for transport to the port.
While some mines in the central provinces pay 10 and 12 francs per ton for transport to the port of embarkation, the mines in Goa achieve the same result with an expense of 2 to 4 francs. These savings make it possible to compete on the market with some of India's production centers.