﻿82 
  TWENTY-FIRST 
  REPORT 
  ON 
  THE 
  STATE 
  CABINET. 
  

  

  of 
  these, 
  so 
  far 
  as 
  I 
  am 
  aware, 
  have 
  been 
  analysed. 
  The 
  peris- 
  

   terite 
  of 
  Thompson, 
  which, 
  as 
  I 
  have 
  shown, 
  is 
  an 
  opalescent 
  

   albite, 
  containing, 
  however, 
  a 
  small 
  portion 
  of 
  lime, 
  belongs 
  to 
  a 
  

   Laurentian 
  veinstone, 
  and 
  is 
  accompanied 
  by 
  quartz 
  and 
  orthoclase. 
  

   Portions 
  of 
  a 
  feldspar 
  are 
  occasionally 
  intermixed 
  with 
  the 
  

   pyroxenic 
  and 
  hornblendic 
  strata 
  accompanying 
  the 
  Laurentian 
  

   limestones. 
  This 
  in 
  some 
  cases 
  is 
  orthoclase, 
  as 
  remarked 
  above, 
  

   but 
  at 
  other 
  times 
  is 
  evidently 
  a 
  triclinic 
  species, 
  giving 
  rise 
  by 
  

   its 
  admixture 
  with 
  hornblende 
  to 
  a 
  kind 
  of 
  diorite. 
  The 
  great 
  

   beds 
  of 
  rock, 
  composed 
  chiefly 
  of 
  labradorite 
  or 
  related 
  triclinic 
  

   feldspars, 
  which 
  have 
  been 
  elsewhere 
  described 
  as 
  belonging 
  to 
  the 
  

   Laurentian 
  system, 
  occur 
  in 
  that 
  upper 
  and 
  unconformable 
  division 
  

   which 
  has 
  been 
  designated 
  as 
  the 
  Upper 
  Laurentian 
  or 
  the 
  Lab- 
  

   rador 
  series. 
  

  

  Scapolite. 
  — 
  Under 
  the 
  head 
  of 
  scapolite 
  and 
  its 
  various 
  syno- 
  

   nyms, 
  mineralogists 
  have 
  included 
  a 
  number 
  of 
  dimetric 
  silicates 
  

   allied 
  to 
  the 
  feldspars, 
  and 
  sustaining 
  to 
  one 
  another 
  relations 
  

   similar 
  to 
  those 
  of 
  the 
  different 
  triclinic 
  feldspars 
  ; 
  the 
  extremes 
  

   being 
  dipyre, 
  the 
  least 
  basic, 
  and 
  meionite, 
  the 
  most 
  basic 
  of 
  the 
  

   series. 
  Scapolite 
  abounds 
  in 
  many 
  of 
  the 
  Laurentian 
  veinstones, 
  

   often 
  associated 
  with 
  pyroxene 
  or 
  sphene 
  (sometimes 
  with 
  ortho- 
  

   clase), 
  and 
  frequently 
  in 
  detached 
  crystals, 
  imbedded 
  in 
  calcite. 
  

   It 
  will 
  not 
  improbably 
  be 
  found 
  in 
  the 
  crystalline 
  aggregates 
  

   which 
  make 
  up 
  some 
  of 
  the 
  stratified 
  rocks 
  of 
  the 
  series, 
  and 
  has 
  

   been 
  observed 
  by 
  Giimbel 
  under 
  such 
  conditions 
  in 
  Bavaria. 
  See 
  

   pages 
  47 
  and 
  67. 
  

  

  Phlogopjte. 
  — 
  The 
  crystallized 
  mica 
  of 
  the 
  Laurentian 
  calca- 
  

   reous 
  veinstones 
  is 
  a 
  magnesian 
  mica, 
  and 
  belongs 
  to 
  the 
  species 
  

   phlogopite 
  or 
  biotite. 
  The 
  crystals, 
  which 
  occasionally 
  afford 
  

   laminae 
  two 
  feet 
  square, 
  are 
  found 
  imbedded 
  alike 
  in 
  calcite, 
  dolo- 
  

   mite, 
  apatite, 
  serpentine 
  and 
  pyroxene. 
  Packed 
  close 
  together, 
  

   with 
  but 
  little 
  intervening 
  matter, 
  large 
  crystals 
  of 
  magnesian 
  

   mica 
  sometimes 
  line 
  the 
  walls 
  of 
  veins 
  whose 
  centre 
  is 
  filled 
  with 
  

   apatite. 
  The 
  laminae 
  of 
  the 
  large 
  mica 
  crystals 
  are 
  often 
  con- 
  

   torted, 
  and 
  sometimes 
  hold 
  between 
  them 
  thin 
  plates 
  of 
  calcite 
  or 
  

   quartz, 
  or 
  flakes 
  of 
  plumbago. 
  In 
  one 
  case 
  already 
  noticed, 
  a 
  

   well-formed 
  crystal 
  of 
  apatite 
  was 
  found 
  imbedded 
  in 
  a 
  prism 
  of 
  

   mica, 
  which 
  had 
  evidently 
  crystallized 
  around 
  it. 
  Some 
  of 
  the 
  

   finest 
  crystals 
  of 
  mica 
  of 
  moderate 
  size 
  occur 
  imbedded 
  in 
  serpen- 
  

   tine, 
  or 
  with 
  crystallized 
  pyroxene, 
  in 
  calcite. 
  

  

  

  