Cubic.  Grains  and  granular  masses.  Octahedral  cleavage.  Hardness
3.5  to  4  and  specific  gravity  4.6  to  5.1.  Metallic  luster  and  usually  light
bronze-yellow  in  color.  Streak  black.  Non-magnetic.  Brittle  and  opaque.
(Fe,Ni)S.    Yields  easily  on  fusing  a  magnetic  globule.
Occurs  in  large  quantities  at  Sudbury,  Ontario,  in  association  with
chalcopyrite  and  pyrrhotite.  This  is  the  source  of  most  of  the  nickel  used
in  the  United  States.  Also  in  various  localities  in  Norway,  Sweden,  Scot-
land, Australia,  etc.  There  are  no  deposits  of  economic  importance  in  the
United  States.
An  important  source  of  nickel.  The  output  of  the  Sudbury,  Ontario,
region  for  1906  was  21,490,000  pounds  valued  at  $8,948,834.
WURTZITE,  Schalenblende,  ZnS.
Hexagonal,  ditrigonal  pyramidal  class,  a  :  c=i  :  0.9353.  Crystals  rare.  Formed
artificially.  Consist  of  hexagonal  prism  with  pyramid  and  basal  pinacoid.  Mostly
as  radial  fibrous  masses  associated  with  sphalerite.  Also  compact  massive.  Prismatic
and  basal  cleavages.  Hardness  3.5  to  4.  Specific  gravity  3.98  to  4.07.  Color  dark
brown.  Streak  light  brown.  Resinous  luster.
ZnS,  same  as  for  sphalerite.  Usually  contains  iron  (up  to  8%),  also  cadmium,
sometimes  as  much  as  3.66%  (Mies,  Bohemia).  Easily  soluble  in  cold  concentrated
hydrochloric  acid  while  sphalerite  is  not.
Occurs  generally  in  association  with  sphalerite.  Not  as  common  as  sphalerite.
Some  of  the  important  localities  are  Oruro,  Bolivia ;  Pribram,  Bohemia ;  Butte,
Montana.
ERYTHROZINCITE,  (Zn,Mn)S,  is  a  wurtzite  containing  manganese.  Occurs  at
thick  transparent  plates  in  Siberian  lapis  lazuli.
Greenockite,  CdS.
Hexagonal,  ditrigonal  pyramidal  class,  a  :  c=i  :  0.9364.  Natural
crystals  exceedingly  small  and  rare.  Usually  show  hexagonal  prisms  ter-
minated on  the  one  end  with  an  hexagonal  pyramid  and  on  the  other  with
a  basal  pinacoid.  Pyramidal  and  tabular  habits.  Is  usually  found  as  an
earthy  coating.
