the Ores of Manganese. 



Lustre, imperfect metallic. Colour, dark brownish - black. 

 Streak, of the same colour. 



Brittle. Hardness 6.0 ... 6.5, higher than felspar. Sp. gr. 

 = 4.818, large cleavable individuals from Elgersburg. 



Compound Varieties. Massive; composition granular, indivi- 

 duals strongly coherent. 



Observations. 



The present species is proposed to be named " Braunite" by 

 Dr TURNER and myself, in compliment to our mutual friend 

 CAMMERATH BRAUN of Gotha, a gentleman who has pursued the 

 study of mineralogy with much zeal and success, and to whom 

 Dr TURNER and myself are particularly indebted for a number 

 of specimens of this substance, upon which its mineralogical and 

 chemical examination was founded. From him Dr TURNER ob- 

 tained, when in Germany, the first variety of the species of 

 brachytypous manganese-ore, which I afterwards had the good 

 fortune to examine. Being struck with the facility with which 

 this mineral yields to cleavage in the direction of the faces of a 

 four-sided pyramid, and supposing it to belong to the species of 

 the pyramidal manganese-ore of MOHS, I requested Dr TURNER'S 

 permission to extract the form of cleavage from it, but was much 

 surprised when I could not discover the single cleavage perpen- 

 dicular to the axis, which is so very distinct in that mineral, and 

 has been likewise indicated by Messrs BROOKE and PHILLIPS. 

 Though the mineral cleaves very readily, yet its great hardness, 

 being superior to that of felspar, and a strong connection among 

 the particles, render it extremely difficult to obtain the faces 

 sufficiently smooth and even, to reflect a good image even of a 

 single very luminous spot. I was therefore led to suppose, by 

 several approximate measurements, that the regular octahedron 

 should be considered as the fundamental form of the species ^ 



