TALCOSE SCHIST. 295 



In a few rare instances, it has been found im- 

 bedded in argillaceous schist ; but, as far as I 

 have observed, it is, in, this case, generally small 

 in quantity, and often so very limited as scarcely 

 to deserve notice as a separate rock. 



In all these cases, and more particularly in the 

 two former, it is generally associated with some of 

 those minerals, such as steatite and asbestos, 

 which possess a kind of mineral affinity to talc ; 

 and is also not unfrequently accompanied by 

 small bodies of serpentine. 



The last association to be pointed out, is that 

 with the more extensive masses of serpentine, 

 which is scarcely however sufficiently distin- 

 guished from the former ; since these masses 

 must also be considered as included in the pri- 

 mary strata in which it is found. The boundary 

 between the serpentine and the including rock, 

 in these cases, is not unfrequently observed to 

 consist of talcose schist ; and it moreover some- 

 times happens, that there is a transition between 

 the two rocks, formed by massive scaly talc pass- 

 ing into potstone. 



Talcose schist presents no particular varieties 



