COMPOUNDS OF CERIUM, YTTRIUM, LANTHANUM. 201 



Wavellite. 



Trimetric. Usually in small hemispheres a third or half 

 an inch across, attached to the 

 surface of rocks, and having a 

 finely radiated structure within ; 

 when broken off they leave a stel- 

 late circle on the rock. Some- 

 times in rhombic crystals. 



Color white, green, or yellowish and brownish, with a 

 somewhat pearly or resinous lustre. Sometimes gray or 

 black. Translucent. H. =3*5-4. G. = 2*3. 



Composition. Al 3 19 P 4 + 12aq = Phosphorus pentoxide 

 3516, alumina 38-10, water 26 74 = 100. 1 to 2 per cent. 

 of fluorine is often present, replacing the oxygen. B.B. 

 wiiitens and swells, but docs not fuse. Colors the flame 

 green, especially if previously moistened with sulphuric 

 acid. Moistened with cobalt nitrate, assumes a blue color 

 after ignition ; gives much water in the closed glass tube. 



Diff. Distinguished from the zeolites, some of which it 

 resembles, by giving the reaction of phosphorus, and also 

 by dissolving in acids without gelatinizing. Cacoxene, to 

 which it is allied, becomes dark reddish-brown before the 

 blowpipe, and does not give the blue with cobalt nitrate. 



Obs. Occurs at the slate quarries of York County, Pa., 

 and also at Washington Mine, Davidson County, N. C. ; at 

 Magnet Cove, Ark. It was first discovered by Dr. Wavel, 

 in clay shtte in Devonshire. Occurs also in Bohemia and 

 Bavaria, 



Zepharovichile is near wavellite. 



Mellite or Honey stone. In square octahedrons, looking like a honey- 

 yellow resin ; may be cut with a knife. It is an aluminum mellate. 

 Found in Thuringia, Bohemia, Moravia, etc. 



Dawsonite. Hydrous aluminum-calcium carbonate, from a felsyte 

 dike near Montreal. 



CERIUM, YTTRIUM, ERBIUM, LANTHANUM, DIDYMIUM. 



Known in nature in the condition of fluorides, tantalates, 

 columbates, phosphates, or carbonates, and also as constitu- 

 ents in several silicates. 



Yttrocerite. 

 Massive, of a violet-blue color, somewhat resembling a 



