On Hocks and Minerals from the Karakoram Himalayas. 475 



The grains are apt to be irregular in external form, and seldom 

 exhibit a perfect crystal outline ; besides this they have generally a 

 rather dusty look, as if they contained numerous small enclosure?. 

 We find also one or two grains of a mineral rather irregular in 

 outline, which has two cleavages crossing at a large angle, and 

 exhibits not very high polarisation tints. It is probably monoclinic 

 or triclinic, and a secondary product. In parts of the slide crystal- 

 line granules of iron oxide (? haematite) are fairly abundant, and 

 exhibit a somewhat streaky arrangement. Under the microscope 

 the white spots of the rock consist almost wholly of crystalline 

 quartz, and have a somewhat brecciated aspect. This suggests that 

 the specimen may be from a vein, but the rest of the rock in structure 

 more resembles a schist. There seem to be some slight indications of 

 mechanical disturbance, but if this has occurred it has been followed 

 by very considerable recrystallisation. 



The next specimen (fig. 1) comes from a small boulder on the south 

 bank of the stream flowing from the east through the " maidan " of 

 Gargo. This appears to be a rather compact and hard schist, which 



FIG. 1. Piedmontite Schist, near Gargo Glacier. 



evidently contains a fair amount of white mica in very small scales, 

 and is rather rich in piedmontite. At the first glance the slice 

 exhibits a large number of crystals of piedmontite, similar to those 

 already described, together with small garnets and two micas, one 



