the Ores of Manganese. 129 



has likewise been established as such by Messrs BROOKE and 

 PHILLIPS, and by the Abbe HAUY. Even in the works of the 

 Wernerian school, the pyramidal forms had been long ago de- 

 scribed, in reference to the identical specimen from which the 

 above description was derived. Count BOURNON * mentions an 

 ore of manganese crystallized in regular octahedrons, having 

 their solid angles replaced by low four-sided pyramids ; a form 

 which might be explained upon the supposition, that the variety, 

 Fig. 12., appears in the regular composition represented Fig. 14. ; 

 at least it would be necessary to have these varieties compared 

 again with each other, for the purpose of fixing the species to 

 which they belong. 



Hausmannite is hitherto confined to the porphyry formation 

 near Ihlefeld in the Hartz. It is found in a vein by itself, as 

 \vas observed by Professor GUSTAVUS ROSE. . 



III. UNCLEAVABLE MANGANESE-ORE. 



Psilomelane. 



^ 



Dichter Schwarz-Braunstein, Hausmann, p. 295. 



Compact and Fibrous Black Manganese-ore, or Black Hematite, Jameson, vol. iii. 



p. 261, 262. 



Black Iron-ore, Phillips, p. 232. 

 Untheilbares Mangan-erz, Mohs, vol. ii. p. 486. 

 Uncleavable Manganese-ore, Moks, Trans, vol. ii. p. 418. Id. Haidinger, Edin. 



Journ. of Science, vol. iv. p. 47. 

 Schwarz-Eisenstein, Leonhard, p. 734. 



Regular forms and cleavage unknown. Fracture not observ- 

 able. 



* Catalogue, p. 395. 

 VOL. XI. PART I. 



