ORDER XII. HEXAHEDRAL GLANCE-BLENDE. 31 



sulphur, and silver. The locality quoted of this mineral 

 is the mine of Himmelsfiirst near Freiberg. It had first 

 been distinguished by ROME DE L'ISLE? Mr FREIESLEBEN 

 had given it the name of Schilfglaserz, but it was only of 

 late more accurately described by Mr PHILLIPS. 



ORDER XII. BLENDE. 



GENUS I. GLANCE-BLENDE. 



1. HEXAHEDRAL GLANCE-BLENDE. 



Prismatic Manganese-Blende. JAM. Syst. Vol. III. p. 

 406. Man. p. 288. Sulphuret of Manganese. PHILL. 

 p. 246. Manganblende. BREITH. Hoffm. H. B. IV. 

 2. S. 197. Schwarzerz. HAUSM. I. S. 199. Man- 

 ganglanz. LEONH. S. 370. Manganese sulfurd. HAUY. 

 Tabl. comp. p. 111. Traite', 2de Ed. T. JV..p. 268. 



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



Simple forms. H ; O, Vol. I. Fig. 2. 



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



Cleavage, hexahedron, perfect ; traces of the dode- 

 cahedron. Fracture uneven, imperfect conchoi- 

 dal. Surface rough. 



Lustre imperfect metallic. Colour iron-black. 

 Streak dark-green. Opake. 



Rather sectile. Hardness = 3-5 ... 4-0. Sp. Gr. 

 = 4-014, a cleavable variety. 



Compound Varieties. Massive : composition gra- 

 nular, of various sizes of individuals; faces of 

 composition irregularly streaked or rough. 



OBSERVATIONS. 



1. According to KLAPROTH and VAUQUELIN, the hexa- 

 hedral Glance-blende consists of 



