CERIUM AND YTTRIUM ORES. 207 



oxyd of tin 2*1, protoxyd of manganese 1.9, lime 1*7. In- 

 fusible or nearly so. Decomposed by muriatic acid, evolving 

 chlorine. 



Dif. The brilliant easy transverse cleavage distinguishes 

 monazite from sphene. 



Obs. Occurs near Slatoust, Russia. In the United 

 States it is found in small brown crystals, disseminated through 

 a mica slate at Norwich, Conn. ; also at Chester, Conn., and 

 Yorktown, Westchester county, N. Y. 



Cryptolite. A phosphate of the oxyd of cerium in minute prisma 

 (apparently six-sided,) found with the apatite of Arendal, Norway 

 Color pale wine yellow. Gr=4'6. 



ALLANITE. 



Monoclinic. In oblique rhombic prisms like epidote. 

 Cleavage only in traces. Also massive and in acicular ag- 

 gregations, the needles sometimes a foot long. 



Color pitch-brown, brownish-black, streak greenish or 

 brownish-gray, luster pitchy and submetallic. Opaque or 

 nearly so. Brittle. H=5-5— 6. Gr=3'3— 4*2. 



Varieties and Composition. Allanite, cerine, and orthite 

 are names of different varieties of this species- The last 

 occurs in acicular crystals as well as massive. They consist 

 of silica and alumina, with oxyds of iron, cerium, lanthanum, 

 and lime. They fuse before the blowpipe to a black glassy 

 globule or pearl. 



Dif. Allanite differs from garnet, some varieties of which 

 it resembles, in its inferior hardness, and colored streak. Gad- 

 olinite fuses with more difficulty and glows on charcoal, be- 

 sides gelatinizing in nitric acid. 



Obs. Allanite was first brought from Greenland. It oc- 

 curs in Norway, Sweden, and the Ural. 



In the United States it has been found in large crystals in 

 Allen's vein, Haddam Conn. ; at Bolton, Athol, and South 

 Royalston, Mass. ; at Monroe, Orange county, N. Y. 



Pyrorthite. This appears to be an impure orthite, containing some 

 carbon, in consequence of which it burns when heated. Hence the 

 name from the Greek pur, fire, and orthite. It comes :rom near Fah- 

 [un, Sweden. Mosandrite is related to allanite. 



Cerite. A hydrated silicate ot cerium. Color between clove-brown 

 and cherry-red. Luster adamantine. Crystals hexagonal. From 

 JBastnas, Sweden. 



How is it distinguished from sphene % What is the appearance and 

 composition of allanite 1 what are its varieties? 



