MINERAL  PRODUCTS.

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and  strontianite  (SrC0 3 ).  Strontianite  is  the  more  valuable,  as  by
simple  treatment  with  acids  it  is  readily  converted  into  the  salts  desired ­
  for  commercial  purposes.  It  is,  however,  rarer  than  celestite
and  therefore  has  been  mined  on  a  comparatively  small  scale.  Celestite ­
  and  strontianite  are  readily  determined  before  the  blowpipe,  as
both  of  them  have  a  crimson  flame  due  to  the  element  strontium.
Celestite  can  hardly  be  assigned  a  value  in  the  United  States,  because ­
  heretofore  it  has  not  been  found  in  sufficient  quantities  and  in
positions  accessible  enough  to  make  its  exploitation  profitable,  in
view  of  the  scant  demand  for  it.  During  1913  no  strontium  was  reported ­
  as  mined  in  the  United  States.  There  is  a  small  market  for
strontium  compounds,  as  is  shown  by  the  import  figures.  No  strontium ­
  carbonate,  oxide,  or  protoxide  was  imported  in  either  1911  or
.1912,  but  in  1913  the  total  value  of  imports  of  these  salts  was  $2,284.
Probably  some  strontium  nitrate  was  imported  for  use  in  "  red  fire,”
but  it  is  not  possible  to  obtain  figures  of  the  imports  of  any  salts  of
strontia  except  those  named  above.  Nearly  all  the  strontium  salts
used  in  the  United  States  are  imported  from  Germany.  Strontium
occurs  also  abundantly  in  Sicily.
The  metal  strontium  is  not  commercially  used,  but  its  salts  are
variously  employed.  Of  these  the  hydrate  and  nitrate  are  of
greatest  importance.  A  simple  process  for  obtaining  the  hydrate  is
the  calcination  of  the  carbonate,  strontianite,  where  that  is  available. ­
  The  temperature  required  is  much  higher  than  that  of  ordinary
lime  burning.  Strontium  hydrate  is  used  principally  in  the  recovery
of  sugar  from  beet  molasses.  Strontium  nitrate  is  made  by  dissolving ­
  the  carbonate  in  nitric  acid,  if  the  native  mineral  can  be
procured  sufficiently  free  from  other  bases  that  would  consume  the
acid.  The  carbonate  used  is  sometimes  made  from  the  sulphate  by
fusing  it  with  soda  ash  and  leaching  out  the  sodium  sulphate.  The
chief  use  of  strontium  nitrate  is  in  pyrotechny,  where  it  imparts  a
red  color  to  the  flame.  The  chlorate  and  carbonate  are  also  used  for
this  purpose,  but  to  a  less  extent.  The  chief  users  are  the  manufacturers ­
  of  fireworks  and  makers  of  fusees  used  by  railroads  and  steamships ­
  for  night  signals.
Strontium  in  the  form  of  the  iodide,  bromide,  acetate,  lactate,
arsenate,  phosphate,  and  other  salts  is  used  as  medicine  and  in  the
chemical  laboratory.
Celestite  occurs  15  miles  south  of  Gila  Bend,  Maricopa  County,
Ariz.,  associated  with  gypsum,  sandstone,  and  conglomerates  containing ­
  pebbles  of  coarse-grained  granite.  It  is  found  in  the  form
of  a  bed  or  beds  overlain  and  underlain  in  some  places  by  beds  of
sandstone  and  in  others  by  igneous  flows.  The  bed  with  which  the
celestite  is  directly  associated  is  40  to  50  feet  thick.  Of  this  thickness ­
  the  upper  8  to  10  feet  looked  most  promising  as  a  source  of  the