COMPOUNDS OF ALUMINUM... | 199 
alum is dissolved out. On evaporation the alum crystallizes 
from the fluid in cubic crystals. This is called Roman alum, 
and is highly valued by dyers, because, although the crystals 
are colored red by iron oxide, no iron is chemically com- 
bined with the salt as is usual in common alum. 
Aluminite (Websterite). Another hydrous aluminum sulphate, in 
’ compact reniform masses, and tasteless. From New Haven, in Sussex ; 
Epernay, in France ; and Halle, in Prussia. 
Lewigite is a potassium-aluminum sulphate, containing half the 
water of potash alum. 
Amblygonite.—Lithium-Aluminum Phosphate. 
Triclinic, with cleavages unequal in two directions, mak- 
ing an angle with one another of 1043°. Lustre vitreous 
to pearly and greasy. Color pale mountain-green, or sea- 
green to white. ‘l'ranslucent to subtransparent. H.=6. 
G. =3-3°11. 
Composition. A lithium-aluminum phosphate, Al O; P,+ 
14 (Li, Na) F. B.B. fuses very easily with imtumescence, 
coloring the flame yellowish red to rich carmine-red, owing 
to the lithia present, and traces of green owing to the phos- 
phoric acid. Gives the reaction also for fluorine. 
Obs. Occurs in Saxony and Norway. 
Hebronite is a closely related mineral from Hebron and Mount Mica 
in Maine, and from Redding in Connecticut. 
Herderite is supposed to be an anhydrous calcium-aluminum phos- 
phate with fluorine. 
Durangite. An anhydrous arsenate of an orange-red color, contain- 
ing aluminum, sodium, iron, and some manganese, with over 7 per 
cent. of fluorine. From Durango, Mexico, where it occurs with cas- 
siterite or tin ore. 
Lazulite. 
Monoclinic. In crystals and also massive, of an azure-blue 
eolor. EH.=5-6., G.=3-057. 
Composition. RAI O, P,+aq= Phosphorus pentoxide 46°8, 
alumina 34°0, magnesia 13:2, water 6°0=100. B.B. in the 
closed tube whitens and yields water ; with cobalt solution 
the color is restored; in the forceps whitens, swells, cracks, 
and falls to pieces without fusion, coloring the flame bluish- 
green. 
Obs. From Salzburg, Styria; Wermland, Sweden; Crowder 
Mount, Lincoln County, N.C. ; and on Graves Mountain, 
Lincoln County, Georgia. 

