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Outlines of the Mineralogy and Geology 



Genus Til. — Lead. 



SPECIES T.—COM.MOJ\' SULPHURET OF LB.iD, 



f 



Common Sulphuret of Lead or Galena, Cleavelandf p. 511. Common Lead 

 glance, Jameson, vol. ii. p. 346. Common Galena, Kirwan, vol. ii. p. 216, 

 Galena, ^ikiii,^. 123^ 



External Characters. 



Its colour is dark bluish grey. 



Its lustre alternates from splendent to sliining and glimmering 

 and is metallick. 



It is opaque. 



The streak is similar,> shining and metallick. 



It is soft. 



cube 



The fracture is curved or straight foliated, and in the latter 

 e it has a three-fold cleavage, parallel to the faces of a 

 It is brittle. 



It is very easily frangible. 



The fragments are cubical. 



Its specific gravity is about 7.440 



Chymical Characters, 



Before the Llowrpipe decrepitates slightly, yields sulphureous 



edour and fuses into a slobiile. 



, A 



Geological Situation and Localities. 

 It occurs disseminated in rolled masses of Quartz, at Medford 



and Brighton ; it is very rare, and sometimes incloses 

 crystal of Quartz. 



a minute 



