DOMAIN I. SIDEROUS. 



MODE IV. BASALTON. 



characters. Texture coarse, and of a large grain, mixed 

 with quartz or felspar, but lax, and incapable of 

 the fine polish of basalt or basaltin. 



Hardness marmoric. Fracture commonly 

 even. Fragments blunt and amorphous. 



Weight sometimes siderose, generally grani- 

 tose. 



Lustre glimmering. Opake. 



Colour grey or greenish. 

 Name. As the Italian termination ino designates di- 

 minutives and substances of a finer nature, so 

 that in one is employed to discriminate those of 

 a coarse appearance or large grain. Hence the 

 name basaiton is adopted for another branch of 

 the basaltic family, that called grunstems by the 

 Germans, an appellation alike vague and bar- 

 barous, as are most of those terms derived from 

 the vulgar miners. The most important and 

 beautiful of the grunsteins, a mixture of crystal-? 

 lised siderite with felspar, has been already de- 

 scribed after siderite. By basalton are under- 

 frwSteki. stood the other kinds of grunstein, except the 

 porphyries; being a mixture of coarse basalt, 

 without the splendour or cohesion of that sub- 

 $tance, with either felspar or quartz. Even that 



