﻿76 
  TWENTY-FIRST 
  REPORT 
  ON 
  THE 
  STATE 
  CABINET. 
  

  

  seminated 
  grains 
  of 
  serpentine, 
  in 
  greater 
  or 
  less 
  abundance^ 
  

   characterizes 
  beds, 
  both 
  of 
  pure 
  limestone 
  and 
  of 
  dolomite, 
  in 
  tb@ 
  

   Laurentian 
  series; 
  and 
  beds 
  of 
  pure, 
  or 
  nearly 
  pure, 
  serpentine 
  

   are 
  also 
  met 
  with, 
  sometimes 
  enclosing 
  scales 
  of 
  mica, 
  grains 
  of 
  

   calcite, 
  which, 
  under 
  the 
  microscope, 
  are 
  seen 
  to 
  be 
  fragments 
  

   of 
  Eozoon, 
  or 
  finely 
  disseminated 
  peroxyd 
  of 
  iron, 
  which 
  gives 
  to 
  

   the 
  serpentine 
  a 
  deep 
  red 
  color. 
  Concretionary 
  masses 
  of 
  serpen- 
  

   tine, 
  sometimes 
  exhibiting 
  in 
  the 
  arrangement 
  of 
  different 
  colors 
  

   a 
  banded 
  or 
  agatized 
  structure, 
  are 
  often 
  met 
  with, 
  imbedded 
  in 
  

   the 
  limestones, 
  and 
  generally 
  have 
  a 
  nucleus 
  of 
  white 
  granular 
  

   pyroxene. 
  These 
  masses 
  may 
  vary 
  from 
  a 
  few 
  inches 
  to 
  a 
  foot 
  or 
  

   more 
  in 
  diameter. 
  

  

  I 
  have 
  already 
  elsewhere 
  described 
  the 
  composition 
  of 
  the 
  Lau- 
  

   rentian 
  serpentines, 
  their 
  low 
  specific 
  gravity 
  and 
  pale 
  colors 
  — 
  

   characters 
  which 
  are 
  due 
  to 
  the 
  small 
  amount 
  of 
  oxyd 
  of 
  iron, 
  and 
  

   the 
  large 
  proportion 
  of 
  water 
  (equal 
  to 
  about 
  fifteen 
  per 
  cent) 
  

   which 
  enters 
  into 
  their 
  composition. 
  These 
  characters, 
  together 
  

   with 
  that 
  of 
  the 
  constant 
  absence 
  from 
  them 
  of 
  chrome 
  and 
  nickel, 
  

   serve 
  to 
  distinguish 
  the 
  Laurentian 
  serpentines 
  of 
  North 
  America 
  

   from 
  most 
  others 
  known, 
  and 
  to 
  connect 
  them 
  with 
  those 
  from 
  the 
  

   old 
  rocks 
  of 
  Scandinavia, 
  with 
  which 
  they 
  have 
  a 
  close 
  resemblance. 
  

  

  An 
  analysis 
  of 
  the 
  chrysotile 
  from 
  a 
  narrow 
  vein 
  traversing 
  the 
  

   Eozoon 
  rock 
  of 
  Petite 
  Nation 
  seigniory, 
  Quebec, 
  gave 
  me, 
  silica^ 
  

   43.65; 
  magnesia, 
  41.57; 
  protoxyd 
  of 
  iron, 
  1.46; 
  water, 
  13.48= 
  

   100.16. 
  

  

  Chrysolite. 
  — 
  This 
  species, 
  which 
  is 
  found 
  in 
  the 
  crystalline 
  

   limestones 
  of 
  Somma, 
  and, 
  according 
  to 
  Rose, 
  occurs 
  with 
  the 
  

   serpentines 
  of 
  Snarum, 
  is 
  known 
  in 
  the 
  crystalline 
  limestones 
  of 
  

   Bolton, 
  Massachusetts, 
  under 
  the 
  name 
  of 
  boltonite, 
  which 
  Messrs. 
  

   Lawrence 
  Smith 
  and 
  Brush 
  have 
  shown 
  to 
  be 
  a 
  pure 
  magnesia- 
  

   chrysolite. 
  I 
  place 
  it 
  in 
  the 
  list 
  of 
  Laurentian 
  minerals, 
  on 
  the 
  

   authority 
  of 
  Messrs. 
  Horton 
  and 
  Beck, 
  according 
  to 
  whom, 
  bol- 
  

   tonite 
  occurs 
  in 
  several 
  localities 
  in 
  limestone, 
  associated 
  with 
  

   spinel 
  and 
  hornblende, 
  in 
  Orange 
  county. 
  New 
  York 
  (Beck, 
  

   Mineralogy 
  of 
  New 
  York, 
  page 
  283). 
  It 
  is 
  not 
  improbable 
  that 
  

   this 
  mineral 
  may 
  be 
  more 
  widely 
  diffused, 
  and 
  it 
  has 
  perhaps 
  been 
  

   confounded 
  with 
  chondrodite, 
  like 
  which 
  species, 
  and 
  like 
  serpen- 
  

   tine, 
  it 
  will 
  probably 
  occur 
  both 
  in 
  beds 
  and 
  in 
  veinstones. 
  

  

  Chondrodite. 
  — 
  This 
  fluosilicate 
  of 
  magnesia 
  occurs 
  in 
  calcareous 
  

   veins, 
  generally 
  with 
  spinel, 
  in 
  numerous 
  localities 
  in 
  the 
  United 
  

  

  