155 



TAB. LXXV. 



Is the same substance as the last. The crystallization is a 

 very curious one. The edges being truncated adding 6 faces, 

 which, with the truncations and the solid angles spoken of 

 in the last, make 14 faces. The latter faces may be trian- 

 gular, like the three bottom ones, or hexangular like that at 

 the top. 



These are on a gangue of somewhat dirty green chlorite 

 and quartz, with pyrites. 



The nature of the accumulation will be seen when we 

 take occasion to figure the primitive form. 



The well known semimetal zinc, often used as a principal 

 agent in galvanism, for making of brass, &c. is extracted 

 from this ore. 



