GRANITE. 241 



I am under the necessity, as already men- 

 tioned, of introducing into this synopsis, in the 

 manner of an appendix, four substances, of some 

 of which, at least, the places have not been 

 thoroughly described. They appear, as far as 

 can be judged, to have a greater analogy to 

 granite than to any other family. Hereafter, 

 when their geological connections and characters 

 are better known, and when it is determined 

 w r hether they are really entitled to places among 

 rocks, they may be removed, should it prove 

 necessary, to some other part of the system. 



A. Mica and compact felspar, sometimes contain- 

 ing garnets. Weiss stein Whitestone. 



It is possible, that this substance rather ap- 

 pertains to gneiss ; if the structure is schistose, 

 us is said, it is the more likely ; but the only spe- 

 cimens which have come under my notice, were 

 not characterized by that structure. 



B. Felspar, quartz, smaragdite sometimes con- 

 taining cyanite and garnets of Styria and Corsica. 



C. Smaragdite and compact felspar. 



D. Splendent Diallage- (Schiller spar) and com- 

 pact felspar. Of Corsica, &c. 



This rock is found accompanying serpentine, 

 R 



