of Boston and its Vxcinity 



143 



Chymical Character 

 It is infusible before the blowpipe. 



Geological Situation and Localities, 



It occurs massive, disseminated and in veins of various thick' 

 iiess, in Argillite and Greenstone, at Charlestown, "WatertowDy 

 Waltham, Brighton, Danvers, and in Amygdaloid at Brighton 

 and at the Lower falls in Newton. 



MemarTc. 



The green colour of this variety is probably produced by Epi- 



dote. 



Subspecies II. — Granular Limestone, 



Granular Limestone. Cleaveland, p. 151. Jameson, vol. i. p. 484. Foliated 



Kirwan 



aikiuy p. 175. 



External Characters, 



■^^ 



Its colours are white, grey and blue. Of white, it occurs bluish 



white, and reddish white ; of grey, ash grey and bluish grey ; 



of blue, greyish blue. 



Its lustre is shining and glimmering; .and is vitreous and 

 pe arly . 



It is translucent at the edges. 

 It is amorphous. 



The streak is whitish. 



w 



It is semi-hard. 



The fracture is straight foliated 5 fine grained uneven and 

 splintery. 



It is easily frangible. 



