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VIII. Mineralogical Account of the Ores of Manganese. By 

 W. HAIDINGER, Esq. F. R. S. E. 



(Read December 17. 1827.) 



_LHE mineralogical determination of those species, the chief 

 constituent of which is Manganese, has been for a long time des- 

 titute of that precision at which other species had long arrived, 

 whose chemical constitution was better known. Two years ago I 

 published, in a memoir " On the Crystalline Forms and Properties 

 of the Manganese-Ores*" the most accurate information I could 

 then collect, partly from some works on mineralogy, partly from 

 my own observations. In the general descriptions which I propose 

 giving here for the mineralogical illustration of Dr TURNER'S 

 account of their chemical properties, I have availed myself of 

 the corrections given in the translation of the same paper in 

 POGGENDORFF'S Annals by Professor GUSTAVUS ROSE, who has 

 corrected or verified the angles given, and compared them again 

 with nature ; so that the statements have gained a considerable 

 accession of authority. I have added the description of that 

 species, which consists of the anhydrous peroxide of manganese, 

 and which, from the difference of its properties from all the rest, 

 whatever may be the mode of its formation, should be consi- 



dered as a species of its own. 



f. u*-> ' 



It is attended with considerable difficulty, and offers but 

 little advantage, to collect the synonyms used by the older mi- 

 neralogical authors, the two names Grey Manganese and Black 

 Manganese, and other ones of a similar cast, having been almost 



* Edinburgh Journal of Science, vol. iy, p. 41. 



