COMPOUNDS OF CERIUM, YTTRIUM, LANTHANUM. 203 
Rogersite. A hydrous columbate of yttria, in whitish crusts, on 
samarskite. From N. Carolina. 
Monazite. 
Monoclinic. In modified oblique rhombic prisms ; ZA F 
=93° 10°. Perfect and brilliant basal cleavage. Observed 
only in small imbedded crystals. , 
Color brown, brownish red; subtransparent to nearly 
opaque. lustre vitreous inclining to resinous. Brittle. 
Heo. G. = 4°8-5'1, 
Composition. A phosphate containing cerium, Jantha- 
num, yttrium, didymium and thorium, with also a little 
tin, manganese, and lime. B.B. it colors the flame green 
when moistened with sulphuric acid and heated. Difficultly 
soluble in acids. 
Diff, The brilliant easy transverse cleavage distinguishes 
monazite from sphent. 
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 cerium phosphate in minute prisms (apparently six- 
sided), found-with the apatite of Arendal, Norway. Color pale wine- 
yellow. G.=4°6. 
Churchite. A phosphate of cerium, didymium and calcium ; from 
Cornwall. 
Aenotime. An yttrium phosphate having a yellowish-brown color, 
pale brown streak, opaque, and resinous in lustre. Crystals square 
prisms, with perfect lateral cleavage. H.—4-5. G.=4°6. Infusible 
alone before the blowpipe ; insoluble in acids. From Lindesnaes, 
Norway ; Ytterby, Sweden ; gold washings of Clarkesville, Ga., and 
McDowell County, N. C. 
Parisite. Is a carbonate containing cerium, lanthanum, and didy- 
mium, with fluorine. From New Granada. 
Lanthanite. Occurs in thin. minute tables or scales of whitish or 
yellowish color, and is a hydrous lanthanum carbonate. From Bast- 
nis, Sweden, and Saucon Valley in Lehigh County, Pa. 
Tengerite. An yttrium carbonate. Found in thin coatings at Yt- 
terby, Sweden. 
Rhabdophane. A didymium and erbium phosphate; from Corn- 
wall, with sphalerite (blende), which it resembles. 
Rutherfordite. A blackish-brown vitreo-resinous mineral. From 
the gold mines of Rutherford County, N. C. j 
Allanite, Gadolinite, Keilhauite, and Tscheff kinite, are silicates con- 
taining either cerium or yttrium. 
