﻿78 
  TWENTY-FIRST 
  REPORT 
  ON 
  THE 
  STATE 
  CABINET. 
  

  

  calcite, 
  quartz, 
  mica 
  and 
  black 
  tourmaline, 
  the 
  crystals 
  of 
  the 
  first 
  

   named 
  mineral 
  being 
  sometimes 
  six 
  inches 
  thick, 
  and 
  as 
  much 
  as 
  

   twenty-four 
  inches 
  in 
  length, 
  and 
  those 
  of 
  the 
  dark 
  green 
  horn- 
  

   blende 
  occasionally 
  an 
  inch 
  both 
  in 
  length 
  and 
  breadth. 
  (See 
  

   Geol. 
  Can., 
  pages 
  35 
  and 
  466). 
  This 
  association 
  of 
  pyroxene 
  and 
  

   hornblende 
  has 
  been 
  observed 
  elsewhere 
  in 
  the 
  Laurentian 
  rocks 
  

   (page 
  49). 
  Pargasite 
  is 
  frequently 
  found 
  in 
  the 
  apatite 
  veins 
  in 
  

   Burgess, 
  and 
  sometimes 
  forms 
  the 
  selvage 
  of 
  the 
  vein 
  where 
  this 
  

   cuts 
  a 
  hornblendic 
  gneiss. 
  Although 
  this 
  species 
  frequently 
  occurs 
  

   in 
  the 
  gneissoid 
  rocks 
  near 
  the 
  crystalline 
  limestones, 
  it 
  is 
  less 
  fre- 
  

   quent, 
  as 
  a 
  disseminated 
  mineral 
  in 
  the 
  limestones, 
  than 
  pyroxene. 
  

   In 
  the 
  stratified 
  pyroxenite 
  rocks, 
  small 
  portions 
  of 
  hornblende, 
  

   recognizable 
  by 
  their 
  different 
  crystallization 
  and 
  their 
  darker 
  

   green 
  color, 
  are 
  not 
  unfrequeut. 
  In 
  some 
  localities 
  it 
  appears 
  to 
  

   take 
  the 
  place 
  of 
  the 
  pyroxene, 
  and 
  large 
  beds 
  of 
  hornblende 
  

   rock, 
  passing 
  into 
  diorite 
  and 
  hornblendic 
  gneiss, 
  are 
  met 
  with. 
  

   A 
  radiated 
  green 
  hornblende, 
  actinolite, 
  is 
  sometimes 
  found 
  im- 
  

   bedded 
  in 
  the 
  magnetic 
  iron 
  ores. 
  

  

  Pyroxene. 
  — 
  Eepeated 
  mention 
  has 
  already 
  been 
  made 
  of 
  the 
  

   important 
  rank 
  which 
  this 
  species 
  assumes 
  in 
  the 
  Laurentian 
  vein- 
  

   stones, 
  in 
  which 
  the 
  varieties 
  diopside, 
  sahlite 
  or 
  coccolite 
  often 
  

   form 
  the 
  predominant 
  mineral. 
  Its 
  crystals 
  are 
  sometimes 
  found, 
  

   either 
  alone 
  or 
  with 
  mica, 
  imbedded 
  in 
  calcite, 
  or 
  in 
  contact 
  with 
  

   hornblende, 
  wollastonite, 
  orthoclase, 
  scapolite, 
  garnet, 
  apatite, 
  

   spinel, 
  zircon 
  or 
  sphene. 
  It 
  often 
  assumes 
  a 
  granular 
  form, 
  con- 
  

   stituting 
  what 
  is 
  called 
  coccolite. 
  A 
  white 
  aluminous 
  diopside 
  is 
  

   found 
  with 
  apatite, 
  gieseckite, 
  etc., 
  in 
  Bathurst, 
  Ontario 
  (Geol. 
  

   Can., 
  page 
  467), 
  and 
  the 
  hudsonite 
  of 
  Orange 
  county, 
  New 
  York, 
  

   is 
  a 
  black 
  aluminous 
  pyroxene. 
  

  

  We 
  have 
  already 
  mentioned 
  the 
  pyroxenite 
  rocks, 
  sometimes 
  

   micaceous, 
  and 
  at 
  other 
  times 
  mixed 
  with 
  hornblende, 
  or 
  with 
  

   orthoclase, 
  quartz 
  and 
  sphene. 
  Pyroxene 
  also 
  sometimes 
  occurs 
  

   disseminated 
  in 
  the 
  beds 
  of 
  magnetite, 
  and 
  grains 
  or 
  imperfect 
  crys- 
  

   tals 
  of 
  it, 
  generally 
  of 
  a 
  green 
  color 
  more 
  or 
  less 
  deep, 
  are 
  common 
  

   in 
  the 
  beds 
  of 
  li 
  r.estone, 
  and 
  are 
  also 
  sometimes 
  found 
  in 
  the 
  

   associated 
  quartzites. 
  A 
  pure 
  white 
  granular 
  p}^roxene 
  occurs, 
  

   replacing, 
  like 
  serpentine, 
  Eozoon 
  Canadense. 
  Large 
  masses 
  of 
  a 
  

   similar 
  pyroxene 
  are 
  also 
  frequent 
  in 
  these 
  limestones, 
  generally 
  

   associated 
  with 
  serpentine, 
  which 
  often- 
  incrusts 
  it, 
  and 
  small 
  

   nuclei 
  of 
  this 
  pyroxene 
  frequently 
  form 
  the 
  centre 
  of 
  concretion- 
  

   ary 
  masses 
  of 
  serpentine. 
  

  

  