There are outcroppings of lignite at numerous points on the island, and in the vicinity of Mt. Halcon is found the finest marble yet discovered in this part of the world.

The production of iron ore is reduced by 19 per cent., of anthracite by 14 per cent., of lignite by 70 per cent.

Anthracite and bituminous coal would have belonged especially to primary times, lignites to secondary and tertiary times, and peat to our own epoch, without the peat ever being able to become lignites or the latter coal.