wherry: native element minerals 



455 



Iridiferous Pt, Ir 



TRIGONAL-PALLADIUM GROUP 



Zinc. 



Zn 



Palladium, trigonal Pd 



Osmium, iridiferous Os, Ir 



TIN GROUP. 



Tin 



these, iron and iridium, occur in 

 sufficient amount to be regarded as 

 giving rise to definite varieties. 

 /Included by Dana partly under "iridium" 

 \ and partly under "platinum." 



[New; includes zinc, classed by Dana as a 



\ semi-metal, and the trigonal minerals 

 of the platinum-iron group. 

 Occurrence in nature doubtful. 



C "Allopalladium." May contain isomor- 

 phous silver, gold, and platinum, al- 



\ though none of these occur in sufficient 

 amounts to be regarded as giving rise 



[ to definite varieties. 



["Dark iridosmine," "sisserskite." In- 

 cluded, along with the following min- 

 eral, in the species "iridosmine" by 

 Dana; but there is no definite evidence 

 that it is anything but a variety of 

 trigonal osmium containing variable 

 amounts of iridium and perhaps other 

 metals. 



[ "Light iridosmine," "nevyanskite." In- 

 cluded, along with the preceding vari- 

 iety, in the species "iridosmine" by 

 Dana; but there is no definite evidence 

 that it is anything but a variety of tri- 

 gonal iridium ; may contain isomorphous 

 copper, iron, ruthenium, rhodium, pal- 

 ladium, osmium, and platinum; of these 

 only osmium occurs in sufficient 

 amount to be regarded as giving rise to 

 a definite variety. 



[New; included by Dana in the gold group 

 tetragonal \ but here separated on the basis of dif- 

 ferent crystallization. 



[Occurrence in nature never proved be- 

 yond doubt, although there is a speci- 

 men in the U. S. National Museum from 

 placers in California which has every 

 appearance of being a natural product. 



(New; includes all metals occurring in the 



\ amorphous state. 

 Known to early German miners, but its 

 character was first recognized by 

 Cornu, Z. Chem. Ind. Kolloide, 4: 187. 

 1909. (Not in Dana.) 



Iridium, osmiferous Ir, Os 



Sn 



I 



COLLOIDAL GROUP. AMORPHOUS 



Silver, amorphous Ag 



