EXTRA-LIMITAL SPECIES. 
457 
WOLFRAM. 
Ferruginous Oxide of Tungsten. Cleaveland. 
Colour dark greyish, or brownish black. Crystallized and massive. Lustre brilliant, often 
metallic. Opaque. Brittle. Hardness 5.0 to 5.5. Sp.gr. 7.11 to 7.40. Composed of 
tungstic acid 67.00, oxide of iron 18.00, oxide of manganese 6.25, silica 1.50. 
Lane’s mine, and Trumbull, Connecticut. 
Min. — Part II. 
58 
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