478 MINERALS IN THE [Deceniber:, 



talc, it forms the soapstone rock, which is much ustd in 

 the city. 



Serpentine, Gemeine?^ Serpentine, W. Roche Serpen- 

 tineusc. H. 



"Near Westchester this miricral occurs very abun- 

 dantly, and is used for common building stone. Colour, 

 from light to dark green. It also occurs in Montgomery 

 county. 



Talc, Gemeiner Talc, W. Talc hexagonal et lami- 

 naire. H. 



Talc forms a considerable portion of the rocks known 

 by the name of soapstone, on the Schuylkill, about ten 

 miles. It does not occur here crystallized, but laminated 

 and compact, of a greenish gray colour. Some specimens 

 from this quarry, are of a rich green colour, semitranspa- 

 rent, and generally connected with bitter spar^ or the 

 magnesian rhomboidal carbonate of lime. 



Ashe sf lis, Asbeste, H. Asbest. W. 



Fibrous asbcstus is found in the serpentine rocks 

 about one mile north of Westchester, and in many other 

 places in Chester and Montgomery counties, it occurs 

 also in very delicate fibres on cjuartz crystallized, in the 

 hornblende quarrv, end of canal road. 



Mountain Cork, Bergkork, V\^. Asbeste tressL H. 



It occurs at l4ondon grove, on the property of John 

 Jackson, m granular white limestone. It is v.hite, and 

 when the j^ieces are coividerably thicker than paper, 

 spongy. 



