whkrry: sulfide minerals 



495 



5:6 TO 3:4 DIVISION 



UNNEITE GROUP. ISOMETRIC. 



Linneite C0S.C02S3 



Siegenite . 



.a;(CoS.Co2S3).- 



3'(NiS.Ni2S3) 



Polydymite NiS.Ni2S3 



PYRRHOTITE GROUP. HEX- 

 AGONAL 



Pyrrhotite FeSi-1.2 



STERNBERGITE GROUP. ORTHO- 

 RHOMBIC 



Stembergite AgFe2S3-4 



Leucopyrite FeAs.Fe2As3 



Daubreelite FeS.Cr2S3 



1:2 DIVISION 



PYRITE GROUP. ISOMETRIC- 

 PYRITOHEDRAL 



Hauerite MnS2 



Pyrite FeS2 



Nickeliferous 



var (Fe,Ni)S2 



Arsenof errite . . ^ FeAs2 



Smaltite C0AS2 



Cloanthite NiAs2 



Laurite RuS2 



Sperrylite PtAs2 



COBALTITE GROUP. ISOMETRIC- 

 TETARTOHEDRAL 



Part of Dana's "intermediate division." 

 Marked off but not named by Dana. 



"Linnaeite;" includes "carroUite" (Dana 

 No. 82), shown to be a mixture by Mur- 

 \ doch, op. cit., p. 37; also "sychnodymite," 

 which is apparently similar; compare Zam- 

 bonini, Riv. mitt, crist. Ital. 47: 40. 1916. 



Regarded as an isomorphous series, of which 

 the preceding and following are end mem- 

 bers. 



f Has been assigned another formula, but the 

 \ analyses agree as closely as could be ex- 

 [ pected with this one. 



New. 

 "/3-pyrrhotite." 



.New. 

 f "Argentopyrite," "frieseite," etc.; composi- 

 { tion not certain; compare Zambonini, 

 [ loc. cit. 

 Included by Dana under loellingite, but 

 apparently independent. 

 Meteoritic; shows cleavage in one direction 



. Dana's "disulfides " 



Part of Dana's "pyrite group.' 



"Bravoite;" the so-called "cobalt-nickel- 

 pyrite" contains cobalt also. 



Includes "bismutosmaltite" and "chathara- 

 ite," apparently mixtures. 



{ This and the preceding form limited iso- 

 { morphous mixtures, but the series has 

 [ not received a separate name. 



I New; includes minerals of this division con- 

 taining two different non-metals; compare 

 Bragg, X-rays and Crystal Structure, p. 

 154. 1916. 



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