PHYSIOGRAPHY. 289 



Yttro-Tantalite Zinkenite. 



3, It occurs at Finbo and Broddbo, near Fahlun in Sweden with Al- 

 bite and Beryl, and is imbedded in Quartz. 



YTTRO-TANTALITE. Monotoraous Eru- 

 ihron e-Or e. 



Primary form. Octahedron with a square base ? P on 

 P over the base =129 32'. 



In grains. 



Cleavage in one direction pretty distinct. ' Fracture con- 

 choidal, uneven, granular. 



Lustre, iron-black, brownish black, yellowish brown. 

 Streak grey, or greyish white. Translucent to opake. 



Bcittle. Hardness, scratches glass. Sp. gr. =5*39 . . . 

 5-88. 



1. It is infusible before the blow- pipe. In a powerful heat it assumes 

 a yellowish or white color. It fuses with borax into a glass colored by 

 iron. It is not attacked by acids. 



2. Jinalysis. 

 By BERZEL.IUS. 



3. It occurs at Ytterby, and near Fahlun in Sweden. 



ZEAGONITE. (See Gismondin.) 

 ZEOLITE. (See Mesotype.) 



ZINKENITE. Peritomous Antimony-Glance. 

 PARTSCH. 



Primary form, Right rhombic prism. M on M = 120 

 39'. 



VOL. ii. 26 



