The few specimens we obtained of its rocks consisted of the different varieties of talcose formation, with quartz and jasper.
It is a kind of nephrite or jade, a mineral which usually occurs in talcose or magnesian rocks.
This pigment comes in two forms: as asbestine and as talcose (talc, etc.).
Thus feldspar, on being pulverized, yields potash; talcose slate yields magnesia; marls yield lime, etc.
On some of them the coal-beds form part of the cliffs along the shore; on others, copper is found in a chlorite and talcose slate.