166 DESCRIPTIONS OF MINERALS. 



tube ; but in the open tube, yields sulphurous fumes and a 

 white sublimate of arsenous oxide. B.B. on charcoal yields 

 sulphur and arsenic and a magnetic globule ; with borax a 

 cobalt-blue globule. 



Diff. Unlike smaltite affords sulphur, and has a reddish 

 tinge in its white color. 



Obs. From Sweden, Norway, Siberia, and Cornwall. 

 Most abundant in the mines of Wehna in Sweden, first 

 opened in 1809. 



Niccolite. — Copper Nickel. Arsenical Nickel. 



Hexagonal. Usually massive. Color pale copper-red. 

 Streak pale brownish-red. Lustre metallic. Brittle. H.=: 

 5-5-5. 0. = 7 -3-7 -7. 



Composition. Ni As = Nickel 44, and arsenic 56 ; some- 

 times part of the arsenic is replaced by antimony. Gives off 

 arsenical (alliaceous) fumes before the blowpipe, and fuses to 

 a pale globule, which darkens on exposure. Assumes a 

 green coating in nitric acid, and is dissolved in aqua-regia. 



Diff. Distinguished from pyrite and linnseite by its pale 

 reddish shade of color, and also its arsenical fumes, and 

 from much of the latter by not giving a blue color with 

 borax. None of the ores of silver with a metallic lustre 

 have a pale color, excepting native silver itself. 



Obs. Accompanies cobalt, silver, and copper ores in the 

 mines of Saxony, and other parts of Europe ; also sparingly 

 in Cornwall. 



It is found at Chatham, Conn., in gneiss, .associated with 

 white nickel or cloanthite. 



Skutterudite. 

 terud, Norway. 



Breithauptite or Antimonial Nickel. Ni Sb=Antimony 67'8, nickel 

 32*2 = 100. It lias a pale copper-red color, inclining to violet. H.=z5 5 

 -6. G.=7"54. Crystals hexagonal. From Andreasberg. 



Gersdorffiie. A nickel arsenosnlpliide ; NiS 2 + Ni As 2 =Ni AsS= 

 Arsenic 45 - 5, sulphur 19*4, nickel 35*1, but varying much in composi- 

 tion. Color sulphur-white to steel-gray. H.=5'5. G. = 5*6-6 S. 



Ullmannite or Nickel Stibine. An antimonial nickel sulphide, con- 

 taining 25 to 28 per cent, of nickel. Color steel-gray, inclining to sil- 

 ver-white. In cubical crystals, and also massive. H.=5-5'5. G.=6*45. 

 From the Duchy of Nassau. 



Orunauite or Bismuth Nickel. A sulphide containing 31 to 38*5 of 

 sulphur, 10 to 14 per cent, of bismuth, with 22 to 40-7 of nickel. 

 Color light steel-gray to silver- white ; often tarnished yellowish. H. = 

 4*5. G.^5'13. From the district of Altenkirchen, Prussia. 



