434 PHYSIOGRAPHY. CLASS n. 



Silber. WERN. Hoffm. H. B. III. 2. S. 38. Gediegen- 

 Silber. HAUSM. I. S. 105. Gediegen-Silber. LEONH. 

 S. 192. Argent natif. HAUY. Traite, T. III. p. 384. 

 Tabl. comp. p. 73. Traite, 2de Ed. T. III. p. 249. 



Fundamental form. Hexahedron. Vol. I. Fig. 1. 

 Simple forms. H (r), Kongsberg, Norway ; O (n) 



Vol. I. Fig. 2., Mexico ; Cs (o) Vol. I. Fig. 34., 

 Kongsberg. 



Char, of Comb. Tessular. 



Combinations. 1. H. O. Vol. I. Fig. 3. and 4. 

 2. O. C. Kongsberg. 



Cleavage, none. Fracture hackly. Surface, the 

 octahedron striated in a triangular direction, 

 parallel to its edges of combination with the hexa- 

 hedron or the icositetrahedron. The remaining 

 faces often rough, but even. 



Lustre metallic. Colour silver-white, more or less 

 subject to tarnish. Streak shining. 



Ductile. Hardness = 2-5 ... 3-0. Sp. Gr. = 

 10-4743, HAUY. 



Compound Varieties. Twin-crystals, compound 

 parallel to one of the faces of the octahedron. Denti- 

 form, filiform and capillary shapes, also reticulated, 

 arborescent and in plates. Often the individuals are 

 still discernible, but frequently also their extent 

 can be no longer ascertained. In the latter case 

 the surface of the dentiform and filiform shapes is 

 longitudinally streaked. Massive : composition 

 scarcely observable, fracture hackly. Plates, form- 

 ed in fissures, also superficial coatings. 



