PHYSIOGRAPHY. 211 







Stromeyerite. 



STILPNOMELAN. 



Massive ; composition laminar and granular. Cleavage in one 

 direction perfect. 



Lustre vitreous. Color black. Streak, olive-green to liver- 

 brown. 



Hardness = 3-0 ... 4-0. Sp. gr. = 2-769, BREITHAUPT, 3-0 

 . . .3-4, GLOCKER. 



1. It is found at Obergrund in Silesia. 

 STILPNOSIDERITE. (See Limonite.) 

 STRIEGISAN. 



Primary form. Right rhombic prism. M on M =122 15'. 



Secondary foam, the obtuse angles of the primary form repla- 

 ced so as to give rise to dihedral summits inclining to each other 

 under angles of 107 26', and the lateral edges also replaced. 



Cleavage parallel to the sides and the shorter diagonal of the 

 primary form. 



Lustre vitreous to pearly. Color grey, brown and black. 



Hardness (scale of BREITHAUPT,) =6-0 . . .7-0. Sp. gr. = 

 2 354 ... 2-379. 



1. It is found at Striegis in Frankenberg. 



2. It is probably identical with Wavellite. 



STROMEYERITE. Uncleavable Polypoione- 

 Glance. 



Massive : composition impalpable. Fracture flat con- 

 choidal to uneven. 



Lustre metallic. Color blackish lead-grey. Streak 

 shining. 



Hardness =2-5. Sp. gr. =6.225. 



1. It fuses very easily before the blow-pipe, attended with the odor 

 of sulphureous acid, but without effervescence or the formation of a sco- 

 ria. The globule has a grey color, a metallic lustre, is tarnished on the 

 upper side, is semi-ductile and grey within. It is soluble in nitric acid ; 

 the solution affording the indication of copper on the immersion of an 

 iron-plate, and of silver on the introduction of a copper one. 



