130 



SALTS OF ALUMINA. 



WAVELLITE. 



Trimetric. Usually in small hemispheres a third or half 

 an inch across, attached to tho 

 surface of rocks, and having a 

 finely radiated structure within , 

 when broken off they leave a 

 stellate circle on the rock 

 Sometimes in rhombic crystals. 



Color white or yellowish and brownish, with a somewha 

 pearly or resinous luster. Sometimes green, gray or black 

 Translucent. H=35— 4. Gr=2'23— 2*37. 



Composition : alumina 33'8, phosphoric acid 34*9, watet 

 26 '6, fluorid of aluminium, 4'6. Whitens before the blow- 

 pipe but does not fuse. 



Dif. 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, 

 <a.nd gives the reaction of iron. 



Obs. Near Saxton's River, Bellows Falls, Vt., and also 

 at Washington mine, Davidson Co., N. C. It was first dis- 

 covered by Dr. Wavel, in clay slate in Devonshire. Occurs 

 also in Bohemia and Bavaria. 



Fischerite is another hydrous phosphate of alumina containing less 

 phosphoric acid. Gr=246. Color dull green. Translucent. Some- 

 times in six-sided prisms. From the Ural. 



TURQUOIS. 



In opaque reniform masses without cleavage, of a bluish 

 green color and somewhat waxy luster. H=6. Gr= 

 2-6—3. 



Composition: phosphoric acid 30*9, alumina 44*5, oxyd of 

 copper 3*7, protoxyd of iron 1*8, water 19 , 0=99*9. 

 Before the blowpipe it is infusible, but colors the flame green 

 and in the inner cone becomes brown. Loses its blue color 

 in muriatic acid. 



Dif. Distinguished from bluish green feldspar, which it 

 resemble?, by its infusibility and the reaction of phosphorus. 



Obs. Turquois is brought from a mountainous district in 



What is the usual appearance of Wavellite 1 What is its composi- 

 tion ] What distinguishes it from the zeolites ? What is the color and 

 appearance of turquois ? Its constituents ? How is it distinguished 

 from a variety of feldspar ? Where i? 't found ? 



