BRA.UNSPATH. 



borax it melts -with a slight effervescence. 

 Soluble in muriatic acid, with the evolu- 

 tion of chlorine, leaving a trace of silicious 

 matter. 



Localities. Forms veins in porphyry at 

 OEhrenstock, near Ilraenau ; Elgersburg and 

 Friedrichsroda in Thuringia; Leimbach in 

 Mansfeld ; St. Marcel (see MARCELrNE) in 

 Piedmont; Vizianagram in India, &c. 



Named by Turner and Haidinger in honour 

 of M. Braun, of Gotha. 



Brit. Mus., Case 13. 



Braunite may be distinguished from other 

 ores of Manganese by its g*-eater hardness, 

 and from Hausmannite by the direction of 

 its cleavage being parallel to the faces of 

 the pyramid, instead of being parallel with 

 the bases, as is always the case with the 

 latter mineral. 



Braunspath. See Brown Spar. 



Braunstein, Hausmann. See Haus- 

 mannite. 



Braunsteinkiesel, Werner. See Gar- 

 net. 



Brazilian Ruby. The name given by 

 lapidaries to light rose-coloured Spinelle, and 

 pink- coloured lopaz. 



Brazilian Sapphire. The name given 

 by some authors to light-blue Topaz, and by 

 lapidaries to Indicolite. 



Brazilian Topaz. The name given by 

 lapidaries to gold-yellow Topaz, with a tinge 

 of red. 



Brazilian Tourmaline. The name 

 sometimes given by lapidaries to Brazilian 

 Emerald. 



Brecciated Agate. Agates consisting of 

 fragments of Jasper, Bloodstone, Carnelian, 

 &c., cemented by a paste of Chalcedony. 



M. P. G. Horse-shoe Case, No. 557. 



Breislackite, Nicol; Breislakite, 

 Brocchi, Phillips. A variety of Augite oc- 

 curring in wool-like flexible fibres, of a 

 chestnut-brown colour, at Capo di Bove, 

 amongst the older lavas of Vesuvius. 



BB alone, fuses to a brilliant and magnetic 

 black scoria ; with borax forms a green glass, 

 which becomes colourless on cooling. 



Not apparently acted on by boiling muri- 

 atic acid. 



Name. After Breislak, the Italian geolo- 

 gist. 



31. P. G. Upper Gallery, Table-case B in 

 recess 6 ; Nos. 88 to 135. 



Breithauptite, Haidinger ; or Antimo- 

 NiAL Nickel. A mineral formerly found in 

 the Andreasberg mountains, but long since 

 exhausted. Hexagonal. Occurs in thin 

 hexagonal plates ; also arborescent and dis- 

 seminated. Colour light copper-red, In- 



BREUNNERITE. 63 



dining to violet when fresh fractured. 

 Lustre metallic. Opaque. Streak reddish- 

 brown. Fracture uneven. Brittle. H. 5*5. 

 S.G. 7-54. 



Comp. Ni Sb = antimony 68*6, nickel 31-4. 

 Analysis by Stromeyer : 



Antimony .... 63*73 

 Nickel . . . . . 28-94 



Iron 0-86 



Galena . . . . . 6*43 



99-98 



BB on charcoal the antimony sublimes. 



Locality. The Pyrenees, especially in the 

 neighbourhood of the Pic du Midi d'Ossau. 



Name. After Breithaupt, Professor of 

 Mineralogy at Freyberg. 



Breithauptite has been observed in a cry- 

 stallized form amongst the products of blast 

 furnaces. 



Breunnerite, Dana, Phillips, Brooke §- 

 Miller. Hexagonal, with a perfect rhom- 

 bohedral cleavage. Primary form a rhomb 

 of about 107° 30'. Occurs crystallized, also 

 massive, granular, and fibrous. Colourless, 

 yellowish, or brown. Lustre vitreous, some- 

 times inclining to pearly on cleavage sur- 

 faces. Streak greyish-white. Brittle. Frac- 

 ture flat conchoidal. H. 4 to 4-5. S.G. 3 

 to 3-6. 



Fig. 63. 



Comp. (Mg, Fe, Mn) C. Mg C + Fe C = 

 carbonate of magnesia 42*0, carbonate of 

 iron 58 = 100. 



Analysis from Zillerthal, by Stromeyer : 

 Carbonate of magnesia . 84-79 

 Carbonate of iron. . .13-82 

 Carbonate of manganese . 0*69 



99;30 

 ^5 infusible; gives an iron re-action, be- 

 comes black, and sometimes magnetic. 

 Siowly soluble in muriatic acid when pul- 

 verised. 



Breunnerite usually occurs in detached 

 imbedded crystals, of the primary form, in 

 Chlorite-slate, and Serpentine. It may be 

 distinguished by its brown or yellow colour 

 from the crystals of Bitter Spar, with which 

 it is accompanied, the latter being white or 

 translucent. 



Localities. St. Gotthard; the Zillerthal, 

 and Hall in the Tyrol. The only British 

 locality where it has been met yviih is in 

 E 3 



