630 MINERALOGY 



2. The roasted mineral is not magnetic. 



ARGENTITE, Ag 2 S ; C. and Str. Blackish gray ; H. 



2-2.5; G. 7.2; F. 1.5; I; p. 297. 

 Acanthite, Ag 2 S ; Iron-black; H. 2-2.5; G. 7.25; 



F. 3.5; IV. 



3. When roasted on coal it yields a yellow coat, also reacts 



for germanium, p. 586. 



Argyrodite, Ag 8 GeS 6 ; Black; Str. Grayish black; H. 

 2.5-3; G. 6.27; F. 1.5; I. 



4. When reduced with soda yields tin buttons, also reacts for 



Germanium, p. 586. 

 Canfieldite, Ag 8 (Sn.Ge)S 6 ; Black; Str. Grayish black; 



H. 2.5-3; G. 6.27; F. 1.5-2; I. 

 Z>. With soda and borax in R. F. on coal yields a zinc coat; 6, 



p. 573. 

 SPHALERITE, ZnS; Brown to Black; Str. Light 



brown; H. 3.5-4; G. 4.05; F. 5; I; p. 301. 



E. Yields a green flame when ignited in the forceps. 



MOLYBDENITE, MoS, Lead-gray; Str. Grayish 

 black; H. 1-1.5; G. 4.75; Inf.; Ill; p. 296. 



F. The powdered mineral is well roasted, and dissolved in borax on wire. 



1. The borax bead shows iron; a, p. 575. 

 a. Naturally magnetic. 



PYRRHOTITE, [Fe n S n + i; Bronze; Str. Black; H. 4; 



G. 4.65 ; F. 2.5-3 ; III ; p. 308. 



Pentlandite, (Fe.Ni)S; Yellowish brown; Str. Black; 



H. 3.5-4 ; G. 5 ; F. 2 ; I ; p. 308. 

 Troilite, FeS; Bronze; Str. Black; H. 4; G. 4.75; 



F. 2.5; Massive 

 6. Naturally not magnetic. 



PYRITE, FeS 2 ; Brass-yellow; Str. Brownish black; 



H. 6-6.5; G. 5.03; F. 3; I; p. 313. 

 MARCASITE, FeS 2 ; Pale yellow; Str. Grayish black; 



H. 6-6.5; G. 4.88; F. 3; IV; p. 317. 



2. The borax head shows nickel; a, p. 574. 



MILLERITE, NiS ; Brass-yellow ; Str. Greenish black ; 



H. 4.5 ; G. 4.8 ; F. 2 ; III ; p. 307. 

 Beyrichite, Ni 3 S 4 ; Lead-gray; Str. Gray; H. 3-3.5; G. 



4.70; F. 2. 

 Polydymite, Ni 4 S 5 ; ' Steel-gray ; Str. Grayish black ; 



H. 4.5; G. 5.65; F. 2; I. 



