1818.] VICINITY OF PHILADELPHIA. 475 



ArgiUite, Argile schisteuse tabulaire, H. 



Clay slate occurs on the Norristovvn road, about six- 

 teen miles from the city, of a bluish gray colour. It does 

 not appear to be sufficiently perfect there, to be made 

 use of. 



Zeolite. Zeolith, W. Stilbite. H. 



In the hornblende quarry, at the end of the canal road, 

 about four miles from the city, this mineral occurs radi- 

 ated and incrusting the rocks, of a while colour. It is 

 also found there in crystals, though not very perfect. 



Jasper, Quartz Jaspe rouge, H. 



Jasper of various colours and fine texture, is found in 

 angular and broken pieces, on the shores of the Delaware 

 and Schuylkill, some of which have chalcedonic veins 

 through them. It occurs in place of a rough yellow co- 

 lour, about one mile on this side of Springmills, immedi- 

 ately In the road, in considerable blocks, and contains a 

 small portion of chalcedony and drusy quartz. 



Feldspar, Feldspath, H. W. 



The granite and gneiss rocks of our neighbourhood 

 are, in a great measure, composed of this mineral. A few 

 fine specimens, well crystallized, were found by Mr. Va- 

 nuxem and myself, at judge Peters's quarry, about one 

 quarter of a mile above the upper bridge, in ten-sided 

 prisms, with diedral summits, and one specimen hemi- 

 trope. About a mile up the canal road, on the eastern 

 side, is found a beautiful white variety, associated with 

 .crystallized mica and phosphate of lime. 



