CHLORITE SCHIST. 287 



%. 



verse fracture often presents quartz only, while, 

 on the parallel, the other constituent is visible. 

 In those varieties which resemble fine clay slate, 

 the rock consists almost entirely of an imperfect, 

 or argillaceous, foliated chlorite, finely laminar, 

 with an earthy aspect on the cross fracture, and a 

 shining smooth one on the parallel surfaces. 



The minerals peculiarly essential to the 

 composition of chlorite schist are quartz, and 

 foliated chlorite. Whatever difficulty mine- 

 ralogists may find in assigning a determinate 

 character to the latter substance, it must not be 

 confounded with scaly chlorite ; yet the frequent 

 occurrence of this more definite mineral in chlo- 

 rite schist, and the varying degrees in which 

 foliated chlorite approaches to it, prove that there 

 is an affinity between the two. The green hue of 

 foliated chlorite is the most convenient empirical 

 character by which it can be distinguished from 

 mica, and by which, consequently, chlorite schist 

 can be distinguished from micaceous ; but it 

 must be added, that the former mineral is more 

 tender and more flexible than the latter, and 

 possesses more of that saponaceous feel which 

 characterizes talc. 



