﻿ADIRONDACK 
  MAGNETIC 
  IRON 
  ORES 
  25 
  

  

  are 
  generally 
  considered 
  too 
  refractory 
  for 
  direct 
  smelting; 
  their 
  

   utilization 
  depends 
  upon 
  concentration, 
  to 
  which 
  they 
  are 
  as 
  a 
  

   rule 
  very 
  adaptable. 
  There 
  are 
  large 
  bodies 
  of 
  such 
  ores 
  in 
  the 
  

   Lyon 
  Mountain, 
  Arnold 
  hill 
  and 
  St 
  Lawrence 
  county 
  districts. 
  

   The 
  lowest 
  grade 
  of 
  milling 
  ore 
  that 
  is 
  worked 
  carries 
  about 
  35 
  

   per 
  cent 
  iron. 
  

  

  According 
  to 
  the 
  percentage 
  of 
  phosphorus 
  present, 
  the 
  mag- 
  

   netites 
  may 
  be 
  subdivided 
  into 
  low-phosphorus, 
  Bessemer 
  and 
  

   non-Bessemer 
  grades. 
  There 
  is 
  no 
  well 
  defined 
  connection 
  between 
  

   the 
  distribution 
  of 
  phosphorus 
  and 
  the 
  nature 
  of 
  the 
  ore 
  occur- 
  

   rence. 
  In 
  some 
  districts, 
  as 
  instanced 
  by 
  Mineville, 
  both 
  Bessemer 
  

   and 
  high-phosphorus 
  ores 
  have 
  been 
  produced 
  from 
  contiguous 
  

   deposits, 
  though 
  generally 
  the 
  ores 
  from 
  any 
  one 
  district 
  show 
  a 
  

   fair 
  degree 
  of 
  uniformity 
  in 
  respect 
  to 
  the 
  phosphorus. 
  The 
  leaner 
  

   magnetites 
  are 
  apt 
  to 
  be 
  lower 
  in 
  phosphorus 
  than 
  those 
  having 
  a 
  

   high 
  percentage 
  of 
  iron. 
  The 
  bulk 
  of 
  the 
  low-phosphorus 
  ores 
  has 
  

   been 
  produced 
  at 
  Lyon 
  Mountain; 
  the 
  present 
  concentrates 
  from 
  

   this 
  locality 
  carry 
  less 
  than 
  .01 
  per 
  cent 
  of 
  that 
  element 
  with 
  65 
  

   per 
  cent 
  iron. 
  The 
  non-Bessemer 
  ores 
  range 
  up 
  to 
  about 
  .2 
  per 
  

   cent 
  phosphorus, 
  corresponding 
  to 
  10 
  per 
  cent 
  of 
  apatite, 
  which 
  is 
  

   the 
  containing 
  mineral. 
  The 
  Old 
  Bed 
  group 
  of 
  mines 
  at 
  Mineville 
  

   has 
  furnished 
  most 
  of 
  this 
  grade 
  of 
  ore. 
  

  

  The 
  magnetites 
  carry 
  a 
  variable 
  proportion 
  of 
  sulfur, 
  due 
  to 
  

   admixture 
  with 
  pyrite 
  and 
  more 
  rarely 
  pyrrhotite. 
  The 
  part 
  

   played 
  by 
  these 
  minerals 
  in 
  the 
  composition 
  depends 
  upon 
  the 
  

   geological 
  associates 
  of 
  the 
  ore 
  bodies, 
  and 
  a 
  sharp 
  line 
  can 
  be 
  

   drawn 
  generally 
  between 
  the 
  class 
  which 
  carries 
  any 
  considerable 
  

   proportion 
  of 
  them 
  and 
  the 
  low-sulfur 
  deposits. 
  The 
  presence 
  of 
  

   sulfur 
  above 
  a 
  fraction 
  of 
  one 
  per 
  cent 
  is 
  confined 
  mainly 
  to 
  the 
  

   deposits 
  that 
  occur 
  in 
  the 
  banded 
  gneisses 
  and 
  schists 
  of 
  the 
  Gren- 
  

   ville 
  series, 
  which 
  are 
  themselves 
  impregnated 
  with 
  pyrite. 
  When 
  

   the 
  wall 
  rock 
  is 
  an 
  acid 
  variety, 
  corresponding 
  to 
  granite 
  or 
  syenite 
  

   in 
  mineral 
  composition, 
  sulfur 
  exists 
  only 
  in 
  minute 
  quantity. 
  

   Among 
  the 
  deposits 
  belonging 
  to 
  the 
  former 
  class 
  it 
  is 
  possible 
  

   to 
  find 
  gradations 
  from 
  ores 
  with 
  fairly 
  low 
  sulfur 
  to 
  those 
  in 
  

   which 
  the 
  magnetite 
  is 
  replaced 
  largely 
  or 
  almost 
  completely 
  by 
  

   pyritic 
  minerals. 
  

  

  Local 
  variations 
  in 
  the 
  ores 
  frequently 
  arise 
  from 
  the 
  association 
  

   of 
  pegmatite 
  which 
  may 
  carry 
  magnetite 
  in 
  quantity 
  to 
  make 
  it 
  

   valuable. 
  It 
  has 
  additional 
  interest 
  as 
  affording 
  a 
  number 
  of 
  the 
  

   rare 
  minerals 
  and 
  many 
  that 
  attain 
  unusual 
  crystallographic 
  

   development. 
  Mineville 
  and 
  Lyon 
  Mountain 
  have 
  yielded 
  the 
  

  

  