3IAN0ANESK ORKS. 261 



Composition : protoxyd of manganese 33*2, protoxyd of 

 iron 33*6, phosphoric acid 33*2, with some phosphate oflime. 

 Fuses easily to a black scoria, before the blowpipe ; dis- 

 solves in nitric acid, and gives a violet glass with borax. 



Obs. From Limoges in France. Rather abundant at 

 Washington, Conn., and sparingly found at Sterling, Mass. 



Heterosite is another phosphate of the oxyds of manganese and 

 iron, of a gjreenish-gray or bluish color. Contains 41-77 per cent, of 

 phosphoric acid. Huraulite is a hydrous phosphate of the same oxyds, 

 containing 18 per cent, of water and 38 of phosphoric acid. Occurs 

 in transparent, oblique, reddish-yellow crystals. Both heterosite and 

 hureaulite are regarded as either altered triphyline or triplite. 



Hausmannite. A sesquioxyd of manganese containing 72- 1 per 

 cent, of manganese, when pure. Brownish-black and submetalhc, oc- 

 curring massive and in square octahedrons ; H=5 — 5'5. Gr=47 

 .From Thuringia and Alsatia. 



Braunite. A protoxyd of manganese, containing 69 per cent, of 

 manganese when pure. Color and streak dark brownish-black, and 

 luster submetallic. Occurs in square octahedrons ; H=6 — 65. Gr= 

 48. From Piedmont and Thuringia. 



Manganite. A hydrous sesquioxyd of manganese. Occurs mas- 

 sive and in rhombic prisms. Color steel-black to iron-black. H=4 — 

 45. Gr=43 — 44. From the Hartz, Bohemia, Saxony, and Aber- 

 deenshire. 



Peloconite is an ore of manganese and iron, of a bluish-black color, 

 and liver brown streak, with a weak vitreous luster. From Chili. 



Manganblende, or Alabandine. A sulphuret of manganese, of an 

 iron-black color, green streak, submetallic luster. H=35 — 4. Gr= 

 39 — 40. Crystals, cubes and regular octahedrons. From the gold 

 mines of Nagyag, in Transylvania. 



Hauerite is a sulphuret, containing twice the proportion of sulphur in 

 the last. Color reddish-brown and brownish-black, resembling zinc 

 blende. H=4. Gr=346. From Hungary. 



There is also an arseniuret of manganese, of a grayish-white color, 

 and metallic luster, which gives off alliaceous fumes. G=555. From 

 Saxony. 



Diallogite. A carbonate of manganese. Color rose-red to brown- 

 ish ; streak uncolored. Luster vitreous, inclining to pearly. Translu- 

 cent to subtranslucent. Crystals rhombohedral. H=35. Gr=359. 

 Infusible alone. From Saxony, Transylvania, and the Hartz. Also 

 from Washington, Conn., with triplite. 



GENERAL REMARKS ON THE ORES OF MANGANESE. 



Manganese is never used in the arts in the pure state ; but as an oxyd 

 t is laigely employed in bleaching. The importance of the ore for thia 

 purpose, depends on the oxygen it contains, and the facility with which 



On what does the value of manganese ores depend in the art of bleach 

 ing? 



