MINERALOGY. 459 



SECOND ORDER. 



METALLIFEROUS EARTHS. 

 METALLIC STONE ORES UNITED WITH ACIDS. 



Spathic Iron Carbonate of Iron sometimes occurs 

 plainly crystallized or foliated, and at others in globular 

 or granulate aggregations. Color yellowish-gray, vary- 

 ing to brown ; luster pearly to vitreous ; partially trans- 

 lucent ; when dark-colored, opaque. H. = 3.4 to 4.5. 

 Gr. = 3.6 to 3.9. Found in the rocks at different ages, 

 primary and sedimentary ; occupies large beds in gneiss, 

 grauwacke, and also in the coal formation ; often accom- 

 panies metallic ores ; occurs abundant in the Erzgebirge, 

 Hartz, Styria, and Corinthia. English locality, Corn- 

 wall, Alstonmoor. In the United States it is found in 

 Connecticut, traversing gneiss ; occurs also in Vermont, 

 Massachusetts, New York, and the coal regions of Penn- 

 sylvania. 



Bog Ore Iron Stone occurs either in granular form 

 or in brittle, loosely-aggregated, spongy masses ; earthy 

 and of various degrees of hardness and specific gravitjr ; 

 luster sub-metallic, dull ; color ochrous, dark brown ; 

 fracture brittle, or chonchoidal, opaque. Bog iron ore is 

 often mixed with phosphoric acid, and also with some 

 salts of organic acids formed in marshy grounds. Pro- 

 ceeds from decomposition of other species, and often 

 takes the form of leaves, etc., found in swampy soils. 

 Bog ore is abundant in the United States. Localities, 

 in nearly all the Eastern and Middle States ; in Europe, 

 North Germany, Russia, Sweden, Bohemia, bog ore 

 forms large beds. Found in marshy grounds, in the 



