MINERALOGY. 465 



the United States are remarkable for their extent. They 

 abound in the cliff limestone in the mines of Missouri, 

 Illinois, Iowa and Wisconsin ; the lead region of the 

 latter occupying a space of eighty-seven miles from east 

 to west, and fifty-four from north to south. Occurs in 

 large rich veins and deposits, in the mining regions of 

 the Hartz, Black Forest, Bohemia, Carinthia, and moun- 

 tains of Granada. Plate 32, fig. 6. The lead of com- 

 merce and lead ochre, Bleiglatt, Plumbic ochre (pro- 

 toxyd of lead) is obtained from this ore. It is also 

 employed, in its rough state for glazing common stone 

 ware. For this purpose it is ground into an impalpable 

 powder, and mixed with water and clay; into this liquid 

 the earthen vessel is dipped and then baked. 



Molybdenite or Wasserblei S-ulphuret of Molyb- 

 dena occurs in hexagonal crystals ; scales, or masses 

 thin, foliated or disseminate ; color, light lead-gray ; 

 luster, metallic ; has a greasy feel ; fuses when heated on 

 charcoal, gives off fumes of sulphur, detonizes with 

 saltpeter, and dissolves in nitric acid ; deflagrates with 

 nitre. Occurs in granite and all the allied rocks of the 

 primitive formation in numerous localities in North 

 America, Norway, Sweden, Silesia, and in the Cornish 

 mines in England. II. = 1 to 1.5. G. = 4.5 to 4.6. 



Gray Antimony Antimony Glance Sulphuret of 

 Antimony is found usually in tufts of capillary crystals, 

 sometimes divergent, fibrous, and columnar, at others 

 massive, granular ; color lead-gray to steel-gray, often 

 striated ; luster metallic, iridescent, opaque ; fuses read- 

 ily; on charcoal is absorbed, giving off fumes of sul- 

 phur ; dissolves in muriatic acid with most offensive 

 odor. H. = 2.0. G. = 4.5 to 4.7. This ore affords 

 the antimony of commerce, namely, Crude Antimony 

 20 * 



