MICACEOUS SCHIST. 281 



will be found to consist in the varying propor- 

 tion, colours, compactness, undulation, and dis- 

 tribution of the parts. In Rannoch and Schihal- 

 lien a variety occurs, in which large crystals of 

 mica are superadded to the general composition 

 of the rock. 



The following minerals occur embedded in 

 micaceous schist. The garnets are sometimes 

 perfectly crystallized, at others very obscure. In 

 this latter case, their mineral composition is often 

 so imperfect, that they are scarcely discernible, 

 except by their superior hardness and persistence 

 after the rock has weathered. 



Garnet. Andalusite. 



Actinolite. Pycnite. 



Epidote. Prebnite. 



Tourmalin. Apatite. 



Beryl. Oxydulous Iron. 



Corundum. Pyrites. 

 Staurotide. 



