﻿842 
  

  

  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  The 
  following 
  table 
  gives 
  the 
  composition 
  and 
  fusibility 
  of 
  the 
  

   different 
  feldspar 
  species 
  according 
  to 
  Dana. 
  

  

  •^ 
  I 
  

  

  be 
  

  

  Name 
  

  

  Ortboclase 
  . 
  

   Anorthite 
  . 
  . 
  

   Albite 
  .... 
  

   Oligoclase. 
  . 
  

   Labradorite 
  

  

  Fusibility 
  g,^ 
  

   in 
  scale 
  "* 
  

  

  5.0 
  

   5.0 
  

   4.0 
  

   3.5 
  

   3.0 
  

  

  64.7 
  

   43.2 
  

   68. 
  Y 
  

   64.0 
  

   54.0 
  

  

  Al20g 
  

  

  18.4 
  

   36. 
  Y 
  

   19.5 
  

   24.0 
  

   29.0 
  

  

  ^2 
  

  

  16.9 
  

  

  2.0 
  

  

  Na 
  o 
  

  

  CaO 
  

  

  ... 
  20.1 
  

  

  11.8 
  ... 
  

   9.0 
  3.0 
  

   5.0 
  11.0 
  

  

  FeO 
  

  

  

  

  Occurrence. 
  Deposits 
  of 
  feldspar 
  are 
  found 
  in 
  the 
  eoutbeastem 
  

   portion 
  of 
  the 
  state, 
  near 
  the 
  town 
  of 
  Bedford, 
  about 
  40 
  miles 
  north 
  

   of 
  'New 
  York 
  city. 
  In 
  this 
  region 
  the 
  feldspar 
  together 
  with 
  quartz 
  

   form^ 
  large 
  pegmatite 
  veins, 
  in 
  the 
  augengneiss 
  of 
  that 
  region. 
  

   The 
  width 
  of 
  some 
  of 
  these 
  veins 
  is 
  over 
  50' 
  feet. 
  The 
  spar 
  

   at 
  times 
  forms 
  large 
  masses, 
  at 
  other 
  times 
  it 
  is 
  more 
  or 
  

   less 
  intimately 
  associated 
  with 
  the 
  quartz, 
  necessitating 
  some 
  sort- 
  

   ing 
  after 
  it 
  is 
  quarried, 
  and, 
  when 
  streaks 
  of 
  mica 
  or 
  black 
  tourma- 
  

   line 
  are 
  encountered 
  in 
  the 
  veins, 
  they 
  are 
  usually 
  thrown 
  out. 
  

   The 
  color 
  of 
  the 
  feldspar 
  varies 
  from 
  dark 
  red 
  to 
  a 
  creamy 
  white, 
  

   though 
  most 
  of 
  it 
  is 
  a 
  deep 
  cream. 
  The 
  largest 
  quarry 
  is 
  that 
  

   operated 
  by 
  P. 
  H. 
  Kinkel 
  & 
  Son, 
  where 
  a 
  large 
  amount 
  of 
  quartz 
  

   and 
  feldspar 
  has 
  been 
  taken 
  out 
  during 
  the 
  last 
  10 
  years. 
  The 
  

   feldspar 
  in 
  Mr 
  KinkePs 
  quarry 
  is 
  orthoclase, 
  as 
  can 
  be 
  seen 
  by 
  the 
  

   following 
  analysis: 
  

  

  No. 
  1 
  ~ 
  No. 
  2 
  

  

  SiOa 
  64.97 
  65.85 
  

  

  AlA 
  , 
  20.85 
  19.32 
  

  

  FegOj 
  tr. 
  .24 
  

  

  K20(byloss) 
  13.72 
  14.10 
  

  

  Na^O 
  

  

  H2O 
  (by 
  loss).. 
  46 
  

  

  CaO 
  .56 
  

  

  MgO 
  .08 
  

  

  100.00 
  100.15 
  

  

  