1818.] VICINITY OF PHILADELPHIA. 473 



well as on the opposite side of the Schuylkill. The finest 

 specimens have been found eight miles on Westx^hester 

 road* 



The brown tourmalin, has been found at London 

 grove in carbonate of lime. 



Quartz. Berg Kristal. W. 



This mineral exists in large quantities, and in differ- 

 ent forms around us. 



Amethyst quartz, of a beautiful violet blue, and gra- 

 dation to a light blossom colour, is found occasionally in 

 Chester and Delaware counties. 



Blue quartz, amorphous, is found on the Brandy wine, 

 two miles west of Westchester, and contains zircon. 



Smoky quartz, is found finely crystallized, on the 

 Brandywine, in Chester county. 



Limpid quartz, occurs in large quantities, crystal- 

 lized, generally aggregated, showing only their pyramids, 

 at Perkiomen and Norristown, 



Quartz arenaceous, we have in large quantities on the 

 shores of our rivers, and in the sand and gravel hills west 

 of the city. 



Hornstone, Hornstein, W. Quartz agathe grassier. H. 



This mineral occurs in the gravel hills near the 

 Schuylkill, in small pieces and of a fine texture. On the 

 Easton road, about ten miles and a half from the city, it 

 occurs in large quantities, in place, of a grayish white 

 colour, massive and of a dull splintery fracture. On the 

 road to Springmills, about two hundred yards beyond 

 Barrenhill meeting house, immediately at the cross roads, 

 is found a rock much resembling coarse hornstone. 



