﻿rl24: 
  HEW 
  TOKK 
  STATE 
  MUSEUM 
  

  

  ter 
  and 
  is 
  flaky 
  and 
  brittle. 
  This 
  last 
  variety 
  is 
  more 
  predominant 
  

   in 
  the 
  mines 
  at 
  Fowler 
  than 
  in 
  those 
  at 
  Talcville. 
  

  

  The 
  second 
  quality 
  talc 
  is 
  useful 
  only 
  to 
  a 
  limited 
  extent, 
  as 
  the 
  

   pulp 
  must 
  contain 
  but 
  little 
  gritty 
  or 
  scaly 
  material. 
  

  

  The 
  walls 
  of 
  the 
  talc 
  seam 
  (or 
  seams) 
  were 
  nowhere 
  observed 
  to 
  

   be 
  the 
  gneiss 
  which 
  outcrops 
  between 
  the 
  mines. 
  The 
  talc 
  sometimes 
  

   has 
  an 
  abrupt 
  contact 
  with 
  a 
  highly 
  crystalline 
  white 
  tremolitic 
  

   dolomite 
  ; 
  or 
  there 
  may 
  be 
  an 
  inch 
  or 
  two 
  of 
  williamsite 
  between 
  

   the 
  two. 
  This 
  occurrence 
  is 
  probably 
  due 
  to 
  faulting. 
  Or 
  it 
  may 
  

   pass 
  gradually 
  from 
  first 
  quality 
  fiber, 
  through 
  second 
  class 
  gritty 
  

   material 
  and 
  fade 
  gradually 
  into 
  a 
  wall 
  of 
  tremolitic 
  dolomite 
  or 
  

   schist 
  This 
  condition 
  occurs 
  in 
  mine 
  l^o. 
  5 
  where 
  the 
  gritty 
  talc 
  

   grades 
  into 
  a 
  massive 
  amphibole 
  rock. 
  

  

  C. 
  H. 
  Smyth 
  jr., 
  in 
  vol. 
  17 
  of 
  the 
  School 
  of 
  mines 
  quarterly 
  

   describes 
  the 
  occurrence 
  and 
  formation 
  of 
  the 
  talc. 
  He 
  says 
  "in 
  

   most 
  accounts" 
  it 
  is 
  stated 
  that 
  the 
  talc 
  forms 
  a 
  clearly 
  defined 
  vein 
  

   with 
  walls 
  of 
  granite 
  or 
  gneiss, 
  the 
  vein 
  being 
  penetrated 
  by, 
  and 
  

   including 
  horses 
  of, 
  tremolite." 
  

  

  ^'According 
  to 
  the 
  writer's 
  observations, 
  the 
  talc 
  occurs 
  in 
  the 
  

   form 
  of 
  beds, 
  lying 
  wholly 
  within 
  the 
  schist 
  of 
  the 
  limestone 
  

   formation. 
  

  

  They 
  dip 
  and 
  strike 
  with 
  the 
  rest 
  of 
  the 
  formation 
  and 
  have 
  

   schist 
  for 
  both 
  foot 
  and 
  hanging 
  walls, 
  sometimes 
  with 
  an 
  intervening 
  

   thin 
  layer 
  composed 
  largely 
  of 
  quartz. 
  There 
  is 
  little 
  in 
  the 
  

   character 
  of 
  the 
  beds 
  to 
  suggest 
  a 
  vein 
  formation, 
  while 
  the 
  walls 
  of 
  

   gneiss 
  and 
  granite 
  are 
  wholly 
  lacking." 
  

  

  As 
  to 
  the 
  origin 
  of 
  the 
  talc, 
  Prof. 
  Smyth 
  bases 
  his 
  conclusions 
  on 
  

   the 
  microscopic 
  examination 
  of 
  the 
  talc, 
  and 
  he 
  points 
  out 
  that 
  the 
  

   talc 
  is 
  an 
  alteration 
  product 
  derived 
  from 
  beds 
  of 
  tremolite 
  schist 
  in 
  

   the 
  limestone, 
  and 
  all 
  gradations 
  between 
  the 
  talc 
  and 
  the 
  unaltered 
  

   tremolite 
  can 
  be 
  found. 
  In 
  conclusion 
  he 
  says, 
  " 
  The 
  deposits 
  of 
  

   talc 
  are 
  of 
  complex 
  origin 
  and 
  the 
  process 
  which 
  has 
  led 
  to 
  their 
  

   formation 
  consisted 
  of 
  three 
  distinct 
  stages. 
  First, 
  there 
  was 
  formed 
  

   an 
  impure 
  siliceous 
  and 
  magnesian 
  limestone. 
  Second, 
  this 
  rock 
  

   underwent 
  metamorphism 
  and 
  was 
  converted 
  into 
  enstatite 
  and 
  

  

  a 
  A. 
  Sahlin, 
  Trans. 
  Am. 
  inst. 
  M. 
  E. 
  21. 
  p. 
  583. 
  

   A. 
  Sahlin, 
  The 
  mineral 
  industry. 
  1. 
  p. 
  435. 
  

   C. 
  A. 
  Waldo, 
  The 
  mineral 
  industry. 
  2, 
  p. 
  G03. 
  

  

  