ORDER viri. DODECAIIEDRAL IRON-ORE. 403 



France, in Pomerania, and other countries, sometimes in 

 sufficient quantity for melting. 



3. DODECAHEDRAL IRON-ORE. 

 Frank-Unite. PHILL. p. 226. Franklinit. LEONH. S. 313. 

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



Simple forms. 6, Vol. I. Fig. 2. ; D, Vol. I. Fig. 



31.; B, Vol. I. Fig. 33. 

 Char, of Comb. Tessular. 

 Combinations. 1. O. D. & O. B. B. Sim. Fig* 



155., without the faces marked P. Irregular 



forms, grains. 

 Cleavage, octahedron very indistinct. Fracture 



conchoidal. Surface of all the forms smooth. 

 Lustre metallic. Colour iron-black. Streak dark 



brown. Opake. 

 Brittle. Acts upon the magnetic needle, but does 



not exhibit magnetic poles. Hardness = 60 . . . 



6-5. Sp. Gr. = 5-091. 



Compound Varieties. Massive : composition 

 granular, strongly connected. 



OBSERVATIONS. 



1. The dodecahedral Iron-ore consists, according to BER- 

 THIER, of 



Peroxide of Iron 66-00. 



Oxide of Zinc 17-00. 



Red Oxide of Manganese 16-00. 



Its composition is expressed in the formula Zn + Mn + 

 4 Fe, which corresponds to 17'2 oxide of zinc, 15-7 oxide of 

 manganese, and 67-1 peroxide of iron. It is soluble without 



