﻿88 
  TWENTY-FIRST 
  REPORT 
  ON 
  THE 
  STATE 
  CABINET. 
  

  

  limestone 
  presents 
  in 
  some 
  parts 
  large 
  cubic 
  and 
  cubo-octahedral 
  

   crystals. 
  Two 
  large 
  veins, 
  made 
  up 
  almost 
  entirely 
  of 
  orthoclase 
  

   and 
  highly 
  crystalline 
  magnetite, 
  each 
  mineral 
  often 
  presenting 
  

   cleavage 
  planes 
  of 
  a 
  square 
  inch 
  or 
  more, 
  have 
  recently 
  been 
  met 
  

   with 
  in 
  Buckingham, 
  on 
  the 
  Ottowa. 
  In 
  these 
  veins 
  which 
  inter- 
  

   sect 
  the 
  gneiss, 
  and 
  have 
  a 
  breadth 
  of 
  nearly 
  eighty 
  feet 
  each, 
  

   the 
  magnetite 
  forms 
  more 
  than 
  one-half 
  the 
  weight 
  of 
  the 
  vein- 
  

   stone. 
  Other 
  and 
  perhaps 
  larger 
  veins 
  of 
  magnetite 
  may 
  exist, 
  

   and 
  may 
  have 
  given 
  countenance 
  to 
  the 
  theory 
  of 
  its 
  eruptive 
  

   origin, 
  but 
  it 
  is 
  probable 
  that 
  few 
  of 
  the 
  workable 
  deposits 
  of 
  

   this 
  ore 
  are 
  of 
  the 
  nature 
  of 
  veins. 
  They 
  appear 
  to 
  be- 
  conform- 
  

   able 
  to 
  the 
  stratification, 
  and 
  are 
  cut 
  by 
  the 
  same 
  veins 
  which 
  

   traverse 
  the 
  adjacent 
  gneiss 
  and 
  limestone. 
  Moreover, 
  they 
  are 
  

   impregnated 
  with 
  the 
  same 
  minerals 
  as 
  the 
  accompanying 
  strata 
  ; 
  

   grains 
  of 
  apatite, 
  scales 
  of 
  graphite, 
  calcite, 
  feldspar, 
  pyroxene 
  

   and 
  garnet 
  are 
  occasionally 
  found 
  disseminated 
  in 
  the 
  ore, 
  which, 
  

   by 
  a 
  predominance 
  of 
  some 
  of 
  these 
  mixtures, 
  passes 
  into 
  the 
  

   accompanyiny 
  gneiss, 
  or 
  into 
  hornblendic 
  or 
  pyroxenic 
  rock. 
  

  

  Hematite. 
  — 
  Among 
  the 
  Laurentian 
  rocks 
  of 
  St. 
  Lawrence 
  and 
  

   Jefferson 
  counties. 
  New 
  York, 
  several 
  localities 
  of 
  crystallized 
  red 
  

   hematite, 
  or 
  specular 
  iron, 
  with 
  brown 
  spar 
  and 
  dodecahedral 
  

   quartz, 
  are 
  met 
  with, 
  according 
  to 
  Beck, 
  in 
  small 
  veins. 
  In 
  like 
  

   manner, 
  in 
  the 
  township 
  of 
  Bristol, 
  on 
  the 
  Lac 
  des 
  Chats, 
  specular 
  

   iron, 
  in 
  broad 
  crystalline 
  plates, 
  occurs 
  with 
  quartz, 
  and 
  also 
  with 
  

   calcite, 
  in 
  what 
  appear 
  to 
  be 
  true 
  veins 
  cutting 
  the 
  crystalline 
  

   limestone 
  and 
  the 
  adjoining 
  gneiss. 
  The 
  octahedral 
  peroxyd 
  of 
  

   iron, 
  martite, 
  which 
  I 
  described 
  several 
  years 
  since 
  as 
  occurring 
  with 
  

   green 
  hornblende, 
  orthoclase 
  and 
  quartz, 
  from 
  Munroe, 
  New 
  York, 
  

   is 
  probably 
  from 
  a 
  veinstone 
  (Amer. 
  Jour. 
  Science 
  [2], 
  xiii, 
  372). 
  

  

  The 
  workable 
  deposits 
  of 
  the 
  granular 
  and 
  compact 
  varieties 
  of 
  

   hematite, 
  which 
  constitute 
  the 
  red 
  iron 
  ores 
  of 
  Northern 
  New 
  

   York 
  and 
  of 
  Canada, 
  appear, 
  however, 
  to 
  be 
  in 
  all 
  cases 
  of 
  the 
  

   nature 
  of 
  beds, 
  and 
  the 
  remarks 
  with 
  regard 
  to 
  the 
  relation 
  of 
  

   the 
  magnetic 
  ores 
  to 
  the 
  stratification 
  are 
  equally 
  applicable 
  to 
  

   the 
  present 
  species. 
  Although 
  the 
  great 
  deposits 
  of 
  iron 
  ores 
  in 
  

   the 
  Laurentian 
  rocks 
  are 
  chiefly 
  of 
  the 
  magnetic 
  species, 
  beds 
  of 
  

   red 
  hematite 
  have 
  been 
  described 
  as 
  occurring 
  in 
  MacNab, 
  on 
  

   Iron 
  Island, 
  in 
  Lake 
  Nipissing, 
  and 
  elsewhere. 
  In 
  the 
  Lau- 
  

   rentian 
  region 
  of 
  northern 
  New 
  York, 
  in 
  like 
  manner 
  the 
  mag- 
  

   netic 
  oxyd 
  is 
  the 
  prevailing 
  ore, 
  especially 
  in 
  the 
  eastern 
  portion, 
  

  

  