﻿14 
  Brackett 
  and 
  Williams 
  — 
  Newtonite 
  and 
  Rectorite. 
  

  

  I. 
  II. 
  

  

  Si0 
  2 
  _ 
  _ 
  . 
  _ 
  38-86 
  40-22 
  

  

  A1 
  2 
  3 
  35-20 
  35-27 
  

  

  Loss 
  on 
  ignition 
  23*69 
  22-89 
  

  

  Fe 
  2 
  3 
  0-21 
  0.21 
  

  

  CaO 
  0-31 
  0-54 
  

  

  MgO 
  .__ 
  trace 
  trace 
  

  

  0-99 
  

  

  K 
  2 
  ) 
  

  

  Na 
  3 
  \ 
  

  

  1-73* 
  

  

  0-73 
  

  

  100-00 
  100-85 
  

  

  Water 
  at 
  110°-115°C. 
  .. 
  5-53 
  5-44 
  

  

  If 
  the 
  impurities 
  be 
  disregarded 
  and 
  the 
  silica, 
  alumina 
  and 
  

   loss 
  on 
  ignition 
  in 
  analysis 
  I 
  be 
  recalculated 
  to 
  100 
  per 
  cent, 
  and 
  

   the 
  same 
  be 
  done 
  in 
  analysis 
  II, 
  after 
  first 
  bringing 
  the 
  whole 
  

   to 
  100 
  per 
  cent, 
  the 
  following 
  figures 
  are 
  obtained 
  : 
  

  

  la. 
  Ha. 
  Theory 
  for 
  Al 
  2 
  3 
  .2Si0 
  2 
  .4H 
  2 
  0. 
  

  

  3i0 
  2 
  39-76 
  40-88 
  40'82 
  

  

  A1 
  2 
  3 
  _. 
  36-01 
  35-85 
  34'72 
  

  

  Loss 
  on 
  ignition.. 
  24-23 
  23*27 
  24*46 
  

  

  100-00 
  100-00 
  100-00 
  

  

  Although 
  this 
  compound 
  closely 
  resembles 
  ordinary 
  kaolin 
  

   in 
  its 
  chemical 
  properties, 
  it 
  shows 
  thus 
  a 
  marked 
  difference 
  

   in 
  composition, 
  by 
  containing 
  for 
  the 
  same 
  amount 
  of 
  silica 
  

   and 
  alumina 
  double 
  the 
  quantity 
  of 
  water 
  usually 
  found 
  in 
  

   kaolin. 
  

  

  That 
  an 
  apparent 
  similarity 
  exists 
  between 
  newtonite 
  and 
  

   halloysite 
  when 
  a 
  comparison 
  is 
  instituted 
  between 
  the 
  analysis 
  

   of 
  newtonite 
  calculated 
  on 
  the 
  material 
  dried 
  at 
  110° 
  and 
  the 
  

   published 
  analyses 
  of 
  halloysite 
  where 
  it 
  is 
  not 
  stated 
  whether 
  

   the 
  calculations 
  are 
  made 
  on 
  the 
  air-dried 
  material 
  or 
  that 
  dried 
  

   at 
  the 
  above-mentioned 
  temperature, 
  is 
  shown 
  in 
  the 
  following 
  

   table 
  : 
  

  

  Newtonite. 
  Halloysite 
  (Indian 
  aite.) 
  

  

  la. 
  Ha. 
  HI. 
  IY. 
  

  

  SiO 
  

  

  . 
  39*76 
  

   _ 
  36*01 
  

   . 
  24-23 
  

  

  40882 
  

   35-851 
  

   23*267 
  

  

  39-35 
  

   36*35 
  

   22-90 
  

  

  38-90 
  

  

  AlO 
  

  

  37-40 
  

  

  Loss 
  on 
  ignition 
  

  

  23-60 
  

  

  

  100.00 
  

  

  100.00 
  

  

  98*60 
  

  

  •40 
  CaO 
  

   99-00 
  

  

  99-90 
  

  

  Analysis 
  III 
  is 
  of 
  a 
  soft 
  and 
  IV 
  of 
  a 
  hard, 
  white 
  variety 
  of 
  

   halloysite 
  called 
  indianaite.f 
  H. 
  Pemberton, 
  Jr., 
  who 
  made 
  

  

  * 
  Alkalies 
  by 
  difference. 
  

  

  f 
  Report 
  of 
  the 
  Geological 
  Survey 
  of 
  Indiana, 
  8th, 
  9th 
  and 
  10th 
  Annual 
  Re- 
  

   ports 
  (1876-1878), 
  p. 
  156. 
  See 
  also 
  Sixth 
  Annual 
  Report 
  (1874), 
  p. 
  15. 
  

  

  