X 



of Boston and its Vicinilij. ,i6l 



Chymical Character. 

 It is fusible before the blowpipe into a greyish black enaracl. 



Geological Situation and Localities. 



The large crystals occur imbedded in Granite, at Bedford; 

 the smaller, ia ronnded masses of Granite, at Cambridge, West- 

 Cambridse, and Cbarlestowa. 



SPECIES IX. EPIDOTE, 



Epidote, Cleaveland, p. 297. Pistazite, Jameson, vol. ii. p. 530. Glassy- 

 Actlnolite, Kirwan, vol i. p. 168. Thallite, Mvin, p. 277, 



External Characters. 



Its colour is green ; of which it occurs olive green^ blackish 

 grf en and siskin green ; all the colours are of various intensity, 



-4 



and the siskin green is doubtless owing to tlie intermixture of 



r 



reddish white quartz. 



Its lustre is shining and glimmering, and is vitreo-resinous 



and vitreous. 



It is opaque ; some of the crystallized varieties approach to 



L 



translucent. 



It occurs amorphous, and crystallized iu, 



1. Acicular six-sided prisms. 



S. In four-sided prisms. The crystals are seldom well de- 

 fined, and their forms are determined with difficulty ; they are 

 often fascicularly and promiscuously aggregated ; they are small 

 and very small ; and their surfaces are longitudinally striated, 

 and the four-sided prisms are transversely rent. 



1 



