248 



curs also at Monroe, Conn. ; in New York state in Antwerp, 

 Jefferson county, and in Hermon, St. Lawrence county. The 

 argillaceous carbonate in nodules and beds, is very abun- 

 dant in the coal regions of Pennsylvania. 



S^Uses. This ore is employed extensively for the manufac- \ 

 %ure of iron and steel. ^J 



Thomaite is a carbonate of iron occurring in rhombic prisms. Gr=» 

 3*1. From the Siebengebirge mines. Junkerite has proved to be com 

 inon spathic iron. 



Mesitine spar, (Breurmerite.) A carbonate of iron and manganese 

 occurring in yellowish rhombohedrons of 107° 14'. H=4. Gr=3 - 3— 

 3'6. This includes much of what is called rhomb spar, or brown spat 

 which becomes rusty on exposure. 



Oligan spar. A carbonate of iron and manganese. Angle of rhom 

 bohedron 107° 3'. Color yellow or reddish-brown. Gr=3.75. 





VIVIANITE. 



Monoclinic. In modified oblique prisms, with cleavage 

 in one direction highly perfect. Also radiated, reniform, 

 and globular, or as coatings. 



Color deep blue to green. Crystals usually green at right 

 angles with the vertical axis, and blue parallel to it. Streak 

 bluish. Luster pearly to vitreous. Transparent to translu- 

 cent ; opaque on exposure. Thin laminae flexible. H = 

 1-5— -2. Gr = 2-66. 



Composition: protoxyd of iron 42*4, phosphoric acid 28*7, 

 water 28*9. Loses its color before the blowpipe and be- 

 comes opaque ; and if pulverized, fuses to a scoria, which is 

 magnetic. Affords water in a glass tube, and dissolves in 

 nitric acid. 



Dif. The deep blue color connected with the softness, 

 are decisive characteristics. The blowpipe affords a con- 

 firmatory test. 



Obs. Found with iron, copper and tin ores, and some- 

 times in clay, or with bog iron ore. St. Agnes in Cornwall, 

 Bodenmais, and the gold mines of Vorospatak in Transylva- 

 nia, afford fine crystallizations. In the United States, good 

 crystals have been found atlmleytown, N. J. At Allentown, 

 Monmouth county, and Mullica Hill, Gloucester county, N. 

 J., are other localities. It often fills the interior of certain 

 fossils. Occurs also at Harlem, N. Y., in Somerset and 



For what is spathic iron used ? What is the color and structure of 

 vivianite ] Of what does it consist 1 

 20 



