150 



DESCRIPTIONS OF MINERALS. 



PHCENrXVTLLE. 



q .— 6-3_6-4 Also a variety 4-4'9. Consists of lead, alumina, and 

 water. From Hnelgoet in Brittany, and at a lead mine in Beaujeu ; 

 also from the Missouri mines, with black cobalt, and from Canton 

 mine, Ga. 



Anglesite. — Lead Sulphate. 



Trimetric. In rhombic prisms 

 and other forms. Lateral cleavage. 

 I A I— 103° 43£'. Also massive ; la- 

 mellar or granular. 



Color white or slightly gray or 

 green. Lustre adamantine ; some- 

 times a litte resinous or vitreous. 

 Transparent to nearlv opaque. Brit- 

 tle. H. =2-75-3. G. = 6\L-6-4. 



Composition. Pb O4 S, affording 

 about 73 per cent, of oxide of lead. 

 B. B. fuses in the flame of a candle, 

 and, on charcoal, yields lead with 

 soda. 



Diff. Resembles aragonite and some other earthy species ; 

 but this and the other ores of lead are at once distinguished 

 by specific gravity, and also by their yielding lead in blow- 

 pipe trials." Differs from the carbonate of lead in lustre 

 and in not dissolving with effervescence in acid. 



Obs. Usually associated with galena, and results from its 

 decomposition. Occurs in fine crystals at Leadhills and 

 Wanlockhead, Great Britain, and also at other foreign lead 

 mines. In the L T nited States, it is found at the lead mines 

 of Missouri and Wisconsin ; in splendid crystallizations at 

 Phoenixville, Pa.; sparingly at the Walton gold mine, Louisa 

 County, Va. ; at Southampton, Mass.; in Arizona, and in 

 Cerro Gordo, Cal. 



Caledonite is a lead-and-copper sulphate, of azure-blue color. It is 

 remarkable for a very perfect cleavage in one direction. G.=6 4. 

 From Leadhills and Roughten Gill, England; also from MinelaMotte, 

 Missouri. 



Lead selenate. A sulphur-yellow mineral, occurring in small glob- 

 ules, and affording before the blowpipe on charcoal a garlic odor, and 

 finally a globule of lead. It is named Ktrstenite. 



Crocoite. — Crocoisite. Lead Chromate. 



Monoclinic. In oblique rhombic prisms, massive, of a 

 bright red color and translucent. Streak orange-yellow. 

 H. =2-5-3. G.=5-9-6-l. 



