The rocks of Ceylon are primitive, consisting of granite, gneiss and quartz.

Of these the two latter predominate.

Dolomite also exists in large quantities up to an elevation of five thousand feet, but not beyond this height.
Plumbago is disseminated throughout the whole of both soil and rocks in Ceylon, and may be seen covering the surface in the drains by the road side, after a recent shower.
It is principally found at Ratnapoora and at Belligam, in large, detached kidney-shaped masses, from four to twenty feet below the surface.

The cost of digging and the transport are the only expenses attending it, as the supply is inexhaustible.

Its component parts are nineteen of carbon and one of iron.
It exists in such quantities, in the gneiss rocks that upon their decomposition it is seen in bright specks like silver throughout.
This gneiss rock, when in a peculiar stage of decomposition, has the appearance and consistency of yellow brick, speckled with plumbago.