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150 Outlines of the Mineralogy and Geology 



The fragments are angular and very sharp edged. 



* 



I 



Its specifick gravity is about 3.764, 





Chjmical Character, 

 It is perfectly infusible without addition before the blowpipe. 



Geological Situation and Localities, - 

 It occurs in angular pieces, in alluvial soil at Simon's Hill, 



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and at Lechmere Point, on the banks of Charles river, Gam- 



p 



bridge. 



Subspecies II. — Hornstone, 



Ilonistone, Cleaveland, p. 230. Splintery Hornstone, Jameson, vol. i. p. 161 



TTornstone, Aikin, p« 199. 



External Characters. 



Its colour is grey, between bluish grey and greenish grey. 

 It is dull and waxy. 

 It is translucent at the edges. 

 It is amorphous. 

 It is extremely hard. t 



The fracture is fine splintery, passing into even, and imperfect- 

 ly flat conchoidal. 



I 



It is tough. 



It is difficultly frangible. 



The fragments are indeterminately angular and sharp edged. 

 Its specifick gravity is from about S.67 to S.78. 



Chymical Characters. 



It is infusible before the blowpipe, bat becomes white when 

 long exposed to its action. 



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