Vol. 56.] 



CEYLON" ROCKS AND GRAPHITE. 



Oil 



former. The vein itself is almost entirely made up of plates of 

 graphite, which in the slice are generally perpendicular, with 

 occasional narrow interspaces occupied by a zeolite. 



Pig. -1. — Junction of pyroccene-granulite [below'] and graphite-vein 

 \ahove~\; Ragedara. (X f.J 



In the other specimen, a graphite-v^in g inch wide is shown, 

 and much graphite is scattered through the rock, so as to form a 

 second, more irregular vein. A thin section shows much scaly 

 graphite in a rock composed of calcite or quartz-ealcite mosaic or 

 micropegmatite. Where part of a vein is included in the section, 

 the graphite -scales in it are parallel and closely set. In other 

 parts of the slide the graphite is irregularly arranged. A zeolite 

 is sometimes found between the scales in small quantity. 



These Nilhene specimens differ from those found at Ragedara, in 

 that the graphite-bearing rock is not an ordinary igneous rock as 

 at that locality, but more probably a vein-product whose formation 

 was contemporaneous with the deposition of the graphite. 



