﻿24 
  S. 
  L. 
  Penfield 
  — 
  Graftonite, 
  a 
  new 
  Mineral. 
  

  

  while 
  all 
  other 
  mineral 
  phosphates 
  contain 
  either 
  fluorine 
  or 
  

   hydroxyl 
  radicals, 
  or 
  water 
  of 
  crystallization. 
  

  

  Before 
  the 
  blowpipe 
  graftonite 
  darkens 
  and 
  fuses 
  at 
  about 
  

   2 
  to 
  a 
  globule 
  which 
  is 
  slightly 
  magnetic. 
  The 
  globule 
  

   becomes 
  decidedly 
  magnetic 
  after 
  continued 
  heating 
  on 
  char- 
  

   coal. 
  During 
  fusion 
  in 
  the 
  forceps 
  the 
  mineral 
  imparts 
  to 
  the 
  

   flame 
  the 
  pale 
  bluish-green 
  color 
  characteristic 
  of 
  a 
  phosphate. 
  

   Fused 
  in 
  a 
  sodium 
  carbonate 
  bead 
  in 
  the 
  oxidizing 
  flame, 
  the 
  

   green 
  color 
  characteristic 
  of 
  manganese 
  is 
  obtained. 
  The 
  

   mineral 
  is 
  readily 
  soluble 
  in 
  hydrochloric 
  acid, 
  and 
  if 
  a 
  little 
  of 
  

   the 
  concentrated 
  solution 
  on 
  a 
  watch 
  glass 
  is 
  brought 
  in 
  con- 
  

   tact 
  with 
  a 
  drop 
  of 
  dilute 
  sulphuric 
  acid 
  a 
  precipitate 
  of 
  cal- 
  

   cium 
  sulphate 
  is 
  formed. 
  In 
  the 
  closed 
  tube 
  only 
  a 
  trace 
  of 
  

   water 
  is 
  given 
  off, 
  and 
  at 
  a 
  full 
  red 
  heat 
  the 
  material 
  shows 
  

   signs 
  of 
  fusion. 
  

  

  The 
  crystallization 
  of 
  graftonite 
  is 
  monoclinic, 
  although 
  no 
  

   material 
  for 
  obtaining 
  exact 
  and 
  reliable 
  data 
  has 
  thus 
  far 
  been 
  

   found. 
  The 
  crystals 
  are 
  without 
  exception 
  dark 
  from 
  the 
  

   presence 
  of 
  oxidized 
  triphylite, 
  while 
  the 
  outer 
  surfaces 
  of 
  the 
  

   graftonite 
  itself 
  have 
  undoubtedly 
  suffered 
  more 
  or 
  less 
  oxida- 
  

   tion. 
  In 
  some 
  cases 
  oxidation 
  and 
  decomposition 
  have 
  gone 
  on 
  

   to 
  such 
  an 
  extent 
  that 
  only 
  a 
  rude 
  suggestion 
  of 
  the 
  crystal 
  

   form 
  remains. 
  The 
  crystals, 
  moreover, 
  are 
  either 
  fragmentary, 
  

   or 
  they 
  are 
  attached 
  so 
  that 
  only 
  a 
  portion 
  of 
  their 
  faces 
  are 
  

   developed. 
  The 
  crystals 
  averaged 
  over 
  4 
  cm 
  in 
  greatest 
  diam- 
  

   eter, 
  and 
  admitted 
  only 
  of 
  approximate 
  measurement 
  by 
  means 
  

   of 
  the 
  contact 
  goniometer. 
  

  

  The 
  forms 
  observed, 
  which 
  are 
  represented 
  in. 
  the 
  accom- 
  

   panying 
  figures, 
  are 
  as 
  follows 
  : 
  

  

  a, 
  100 
  

  

  m, 
  110 
  

  

  n, 
  130 
  

  

  e, 
  021 
  

  

  b, 
  010 
  

  

  /, 
  120 
  

  

  d, 
  011 
  

  

  p, 
  111 
  

  

  In 
  establishing 
  the 
  axial 
  ratio 
  the 
  value 
  of 
  /3 
  was 
  derived 
  

   from 
  a 
  direct 
  measurement 
  of 
  the 
  angle 
  made 
  by 
  the 
  edge 
  

   between 
  b 
  and 
  e, 
  fig. 
  2, 
  with 
  the 
  vertical 
  edge 
  between 
  b 
  and 
  n. 
  

   Other 
  fundamental 
  measurements 
  were, 
  b 
  ^ 
  m, 
  =51° 
  and 
  

   b^d 
  = 
  62°. 
  The 
  axial 
  ratio 
  obtained 
  from 
  these 
  values 
  is 
  as 
  

   follows 
  : 
  

  

  a 
  : 
  b 
  : 
  c 
  = 
  0*886 
  : 
  1 
  : 
  0-582 
  ; 
  /? 
  — 
  66° 
  

  

  It 
  must 
  be 
  borne 
  in 
  mind, 
  however, 
  that 
  the 
  fundamental 
  

   measurements 
  are 
  not 
  very 
  reliable, 
  and 
  that 
  the 
  axial 
  ratio 
  

   therefore 
  can 
  only 
  be 
  approximately 
  correct. 
  

  

  A 
  few 
  of 
  the 
  more 
  important 
  measured 
  and 
  calculated 
  angles 
  

   are 
  as 
  follows 
  : 
  

  

  