282 PHYSIOGAPHRY. 



Xenotime. 



Secondary form. The primary having the edges of the 

 base deeply truncated. 



Lustre resinous. Color yellowish brown. 

 Hardness = 4-5 ... 5-5 ? Sp. gr. = 4-557. 



1. Alone before the blow-pipe, it is infusible ; but with soda, it affords 

 a brisk effervescence and an infusible scoria. 



2. Analysis. 



By BERZELIUS. 



Phosphoric acid with a little fluoric acid . . 33-49 



Yttria 62.58 



Sub- phosphate of iron 3-93 



3. It has been found in small, imperfect crystals, near Lindenaes in 

 Norway, in granite with Orthite. 



XYLOKRYPTITE. 



In delicate crystals. 

 Lustre vitreous. Color yellow. 

 1. It occurs in Lignite. Locality not mentioned. 



YELLOW COPPERAS. 



In irregular six-sided tables, and in grains. Lustre pearly. 

 Color yellow. Transparent. 



1. Analysis. 



By ROSE. 

 Sulphuric acid 39-60 



Oxide of iron 26-11 



Alumina 1-95 



Magnesia 2-64 



Silica . . , 1-37 



Water 2967 



2. It is found investing white Copperas in the district of Copiapo, a 

 province of Coquirnbo. 



APPENDIX TO WHITE COPPERAS. 



i. Fibrous Yellow Copperas. 

 In fibrous concretions. 

 Lustre silky. Color yellowish green. 



