.^7 i 



IV« 



IRON ORES. 



239 



Uses. Valuable as an iron ore, though less easily woiked 

 when pure and metallic than the magnetic and hematitic . 

 ores. Pulverized red hematite is used Tpr polishing metals. 

 Red chalk is a well known materia^? red pencil!^ 



9 £"* €■* A &rr J Cj-t'- 



-^ / £ LIMTONITmr^-BROWN IKpN ORE. ^V^^ 



Usually massive, and often with a smooth botryoidal o* 

 6talactitic surface, having a compact fibrous structure within ;' 

 Also earthy. f$. 



Color dark brown to ocher-yellow ; streak yellowish 

 brown to dull yellow. Luster sometimes submetallic ; oftei 

 dull and earthy; on a surface of fracture frequently silky 

 H=5- 5-5. Gr=3-6— 4. 



Varieties and Composition. The following are the princi- 

 pal varieties : 



Brown hematite. The botryoidal, stalactitic and associated 

 compact ore. 



Brown ocher, Yellow ocher Earthy ochreous varieties, 

 of a brown or yellow color. 



Brown and yellow clay iron stone. Impure ore, hard and 

 compact, of a brown or yellow color. 



Bog iron ore. A loose earthy ore of a brownish-black 

 color, occurring in low grounds. 



Composition when pure : peroxyd of iron 85*8, (seven-tenths 

 of which is pure iron,) and water 14 '4 ; or it is a hydrous 

 peroxyd of iron, containing when pure about two-thirds its 

 weight of pure iron. Before the blowpipe, blackens and be- 

 comes magnetic. Gives with borax in the inner flame a 

 green glass. 



Dif. This is a much softer ore than either of the two pre /*\ 

 ceding, and is peculiar in its frequent stalactitic forms, and 

 in its affording water when heated in a glass tube. 



Obs. Occurs connected with rocks of all ages, but ap- 

 pears, as shown by the stalactitic and other forms, to have 

 resulted in all cases from the decomposition of other iron ores, % ; 

 probably the sulphuret. 



This is an abundant ore in the United States. The fol- 

 lowing are a few of its localities. Extensive beds exist a" 

 Salisbury and Kent, Conn., in mica slate; also in the neigh 



— ■ 



What is said of the uses of specular iron ? What is the appearance 

 of brown iron ore? its composition? Describe its varie.ies. Wha 

 ore distinguishing characters ? How does this ore occur? 







