.818.] VICINITY OF I^HILADELPHIA. 477 



fifty yards east of the canal road, just beyond the house of 

 Mr. Caspar Morris. Tiie plates are six inches over; and 

 the hexagonal foi ni of crystaliixation is beautifuily illus- 

 trated by the arrangement of lines, of a dark metallic co- 

 louring matter, either iron or manganese. Green mica is 

 found at Chesnuthill, near the Wichicon, where it is pro- 

 bably coloured by chrome; also near Chester. Mica 

 \Qvy largely enters into the com|)osition of our granite^ 

 gneiss, and mica slate rocks. 



Chlorite. Talc Chlorite. H. Chlorit. W. 



Chlorite of a dark green colour, and in fine particles, 

 is found with quartz at Willowgrovc; and laminatedi 

 near the soapstone quarry on the east side of Schuylkill' 

 Dr. Seybert says, near the Warwick iron works in Ches- 

 ter county, and in Montgomery county near the Schuyl- 

 kill, but I regard the latter rather as a talc rock. 



Hornblende. Gemeiner Hornblend. W, Amphibole* H, 



Large masses of hornblende rock exist on the Schuyl- 

 kill, about two hundred yards above the engine house; 

 and about two miles again above that. It is pretty well 

 crystallized, in a bladed and acicular form, on the canal 

 road. 



Lithomarge, Steinmark. Vv^. Argile Llthomarge. H. 



Cleaveland says, that this mineral occurs in Mont' 

 gomery cour.ty, b does not particularize the spot. 



Steatite. Speckstein. W. Talc Steatite. H. 



Steatite is found in considerable quantities, about ten 

 miles up the SchuylkiU, where, with the connection o 



