OUTLINES OF GEOLOGY. 



71 



mica, but near Easton, Pennsylvania, there is a mica rock, 

 containing imbedded zircon, which has no appearance of 

 stratification. Including these, the rocks of this order are : 



1 . Granite ; 



2. Quartz rock ; 



3. Felspar rock ; 



4. Mica rock 



5. Syenite, composed of quartz, felspar, and hornblende ; 



6. Diorite, or primitive greenstone, composed of felspar 

 and hornblende ; 



7. Hornblende rock; 



8. Pegmatite or Graphic granite, composed of felspar and 

 quartz, and which, by its decomposition, forms 



9. Kaolin, or China clay; 



10. Protogyne, composed of talc, or stealite and felspar; 



1 1. The rocks p, 6, and 7, in which hornblende predomi- 

 nates, appear by their composition to form a red clay : we 

 have seen decided instances of this in the gold region of 

 North Carolina. 



12. At Salisbury, Conn., there are two veins of granular 

 carbonate of lime, traversing gneiss and mica slate rocks, 

 abounding in garnets and staurotide. It therefore can hard- 

 ly belong to any other order than this. 



162. These rocks all contain numerous imbedded miner- 

 als. The most important of these are as follows : 



Topaz, 



Quartz, 



Tourmaline, 



Spinelle, 



Zircon, 



Epidote, 



Garnets, 



Beryl, 



Crysoberyl, 



Pinite, 



Pyroxene, 



Idocrase, 



Hyperstene, 



Diallage, 



Phosphate of lime, 



Lepidolite, 



Petalite, 



Triphane, 



