130 



Mincralogical Jovrnnj^ 



4 



X 



TncTination of 



m. 



MonT 



Reflec. G 



-F 



T on J 





4 



5 on ]VP 



• m 





« on a 



• • 



a on 



S 



u 



i,t 



115^ 36' 



128 35 



116 26 



109 24 



125 32 



Besides this form, the following twin-crystal was frequently noticed 



M on T, or M' on T^ Reflec. G. 115^ 36' 



" 129 35 



'' 109 24 



TonT 



a on «' 

 «' on a' 



u 



u 



cc 



138 32 



c Tn size, they vary from half, to one and a hawfinches in length, by 

 one eighth, to one inch, in diameter. Their planes are very symetri- 

 cally extended, free from sti'iae, and in general possessed of a high 

 degree of lustre- Their color is yellowish green, often quite dark ; 

 and the smaller crystals are semi-transparent. In turning them round 



upon 



sm, hitherto unobserved, so far as my knowl- 

 edge extends, in this species. Whenever the edge formed by the 

 meeting of the planes M and T came opposite my eye, the light whici* 

 flowed through the crystal was of fine emerald green color; whereas 

 opposite the other edges, it was of a yellowish brown. 



Magn 



eight inches to several 



feet in width, and obeying the stratification of the rock, occupies 

 the soutli western summit of the mountain, traversing the gneiss, 

 whose strata are here nearly vertical. The surface being quite 

 steep, no difficulty has been encountered from water in following the 

 ore* One vein has been pursued up the mountain for a distance 



