247 



BISMUTH. 



745. METALLIC. 



a. Crystallized and iridescent. Two small pieces. 



VANADIUM. 



746. VANADATE OF LEAD. 



a. Forming a crust on Galena. 



Note For description, etc., see Dana, Mineralogy, p. 611. This 

 specimen originally belonged to the late Professor Phillips. 



COLUMBIUM, OR NIOBIUM. 



747. COLDMBITE. (Columbate of Iron, Niobite.) 



a. In crystalline fragments. 



Note. This mineral consists of the columbate and tantalate of iron 

 and manganese, the columbic acid being usually twice as much atomically 

 as the tautalic. It often contains also traces of tin, copper, calcium, and 



tungsten. See Dana, Mineralogy, p. 5J7. 







CHROMIUM. 



748. CHKOMITE. (Chrome Iron Ore.) 



a. Massive. 



b. Ditto, from America. 



Note. This mineral usually occurs in serpentine. See Dana, Miner- 

 alogy, p. 154. 



URANIUM. 



749. UEANITE. (Torbernite, Phosphate of Uranium and Copper, 



Uran-mica, Urangliminer.) 



a. Crystallized, from Cornwall. 



b. Ditto, presented by Mr. H. Pound. 



Note . Uran-mica contains about 60 p. c. of uranium. For description, 

 etc., see Dana, Mineralogy, p. 585. 



750. URANINITE. (Pitchblende, Protoxide of Uranium, Uratemnite, 



Uncleavable Uranium Ore.) 

 a. Massive. 



Note. This mineral contains from 60 to 85 p. c. of uranium oxides, 

 with traces of iron, calcium, magnesium, and silicon. 



TUNGSTEN. 



751. WOLFRAMITE. (Wolfram, Tungstate of Iron and Manganese.) 



a. Crystallized. 

 Note. See I>aa, Mineralogy, pp. 601-603. 



