456 DESCRIPTIVE MINERALOGY. 



TROOSTITE. 



Fcmigmous Silicate of Manganese. Tiimnsyn. 



Colour pale asparagus-green, yellow, grey and reddish brown. Crystallized and massive. 

 Primary a rhombohedron. PonPllo^. Lustre vitreous. Transparent to translucent. Hard- 

 ness 5.5. Sp. gr. 4.00 to 4.10. Before the blowpipe, it mclls on the edges. Composed 

 of silica 30.05, protoxide of manganese 46.21, peroxide of iron 15.45, moisture and carbonic 

 acid 7.30. 



Sterling, New-Jersey, with franklinitc. 



TUi\"GSTEN. 



Tungstate of lime. Dana and PhiUips. 



Colour white, grey, yellowish and rcddisli brown. Streak while. Crystallized and massive. 

 Primary an octahedron with a square base. Lustre vitreous, inclining to adamantine. Semi- 

 transparent to translucent. Hardness 4.0 to 4.5. Sp. gr. 6.08. Fuses with difficulty before 

 the blowpipe. Composed of lime 19.40, lungstic acid 80.42. 



Monroe and Trumbull, Connecticut. 



TUNGSTIC OCHPtE. 



Yellow oxide of Tungsten. Ckavdand. 



Colour orange or chrome-yellow to yellowisli grey. Slassive ; earthy and pulverulent. Soft. 

 Sp. gr. 6.0. Assumes a green hue when strongly healed. Composed of oxygen 13.55, 

 tungsten 86.45? 



Lane's mine in Monroe, Connecticut, with tungsten and wolfram. 



URANITE. 



Green Oxide of Uranium. Clcavclanil. 



Colour yellow and green. Crystallized and massive. Primary a right square prism. Lustre 

 pearly upon the face P. Transparent to opaque. Hardness 2.0 to 2.5. Sp. gi-. 3.12. 

 Composed of phosphoric acid, lime, oxide of uranium and water, with traces of fluoric acid 

 and ammonia, etc. 



Middletown, Connecticut, with columbite, etc. ; Chesterfield, Massachusetts, with albite. 



