450 wherry: native element minerals 



a still different system, the tetragonal, is assigned to a group by 

 itself. 



In listing groups it is thought best to give those of the highest 

 crystallographic symmetry first place, and to arrange the others 

 in the order of decrease in symmetry. 



A table of native elements based on the above recommenda- 

 tions follows. Its criticism by anyone interested in the system- 

 atic arrangement of mineralogic data will be welcomed. 



NOTES ON THE TABLE 



The first column includes the names of the species and varie- 

 ties worked out according to the principles above outlined and 

 recommended for adoption. The composition of each species 

 and variety is given in the second column, isomorphous replace- 

 ment being represented by a comma, and the element present in 

 largest amount in each case being placed first. 



Column 3 contains reasons for the names or arrangements 

 adopted, synonyms (in quotations), and references for the min- 

 erals not listed by Dana in either the System of Mineralogy 

 (1892) or the three Appendixes (1899, 1909, 1915). 



NATIVE ELEMENT MINERALS. The chemical elements occurring in nature 



in the free state. 

 NON-METALS (INCLUDING 



"SEMI-METALS") Combined for simplicity. 



[New; includes all non-metals and semi- 

 diamond group, isometric. metals with isometric crystallization, 



arranged in order of the periodic system. 

 The retention of the arbitrary name dia- 

 mond is an exception to the rule for 

 naming polymorphs, but is justified by 

 usage. 



Massive ..C "Bort." 



Black massive C "Carbonado." 



Phosphorus, isometric P l"\? ow .Phosphorus," "^phosphorus." 



( Meteontic; very doubtful. 

 "Yellow arsenic." Occurrence in nature 



Diamond (isometric carbon) C 



Arsenic, isometric As 



Tantalum, columbiferous. . . .Ta, Cb 



reported by Vernadskii, Opuil Opisa- 

 tel'noi Mineralogii (Descriptive Miner- 

 alogy) 1, 1908; Cenlr. Min. Geol., 1912: 

 762. (Not in Dana.) 



