﻿20 
  S. 
  L. 
  Pen 
  field 
  — 
  Graftonite, 
  a 
  new 
  Mineral. 
  

  

  Art. 
  IY. 
  — 
  On 
  Graftonite, 
  a 
  new 
  Mineral 
  from 
  Graf 
  ton 
  y 
  

   New 
  Hampshire, 
  and 
  its 
  Intergrowth 
  with 
  Triphylite 
  ; 
  by 
  

   S. 
  L. 
  Penfield. 
  

  

  Material 
  for 
  this 
  investigation 
  was 
  sent 
  to 
  the 
  author 
  for 
  

   identification 
  by 
  Mr. 
  George 
  L. 
  English 
  of 
  New 
  York, 
  who, 
  

   on 
  being 
  informed 
  that 
  it 
  was 
  probably 
  a 
  new 
  mineral, 
  took 
  

   special 
  pains 
  to 
  secure 
  a 
  supply 
  of 
  it, 
  and 
  has 
  given 
  the 
  follow- 
  

   ing 
  information 
  concerning 
  its 
  occurrence 
  : 
  The 
  mineral 
  was 
  

   found 
  on 
  the 
  south 
  side 
  of 
  Melvin 
  Mountain, 
  about 
  five 
  miles 
  

   west 
  of 
  the 
  village 
  of 
  Grafton. 
  It 
  was 
  irregularly 
  dissemi- 
  

   nated 
  through 
  a 
  coarse 
  crystalline 
  mass 
  of 
  quartz 
  and 
  feldspar, 
  

   probably 
  a 
  pegmatite 
  vein, 
  the 
  feldspar 
  individuals 
  being 
  at 
  

   times 
  fully 
  four 
  feet 
  long. 
  Associated 
  with 
  the 
  new 
  mineral 
  

   in 
  the 
  vein 
  were 
  found 
  beryl, 
  black 
  tourmaline, 
  almandine 
  

   garnet, 
  muscovite 
  and 
  biotite, 
  all 
  crystallized 
  on 
  a 
  rather 
  large 
  

   scale, 
  especially 
  the 
  beryl. 
  All 
  of 
  the 
  new 
  mineral 
  that 
  could 
  

   be 
  found 
  was 
  taken 
  from 
  the 
  vein, 
  and 
  the 
  total 
  output 
  con- 
  

   sisted 
  of 
  a 
  few 
  crystals 
  and 
  a 
  considerable 
  quantity 
  of 
  irregular 
  

   fragments. 
  The 
  crystals 
  and 
  also 
  the 
  fragments 
  present 
  a 
  

   rough, 
  weathered 
  appearance, 
  and, 
  what 
  is 
  unusual 
  and 
  at 
  once 
  

   very 
  striking, 
  they 
  consist 
  of 
  alternating 
  layers 
  or 
  lamellae 
  of 
  

   dark 
  and 
  light 
  material, 
  the 
  lamellae 
  being 
  less 
  than 
  0'5 
  mm 
  in 
  

   diameter 
  and 
  often 
  exceedingly 
  thin. 
  Both 
  the 
  light 
  and 
  the 
  

   dark 
  material 
  gave 
  reactions 
  for 
  a 
  phosphate 
  containing 
  iron 
  

   and 
  manganese 
  as 
  bases. 
  The 
  light 
  material, 
  however, 
  con- 
  

   tained 
  only 
  ferrous 
  iron, 
  while 
  the 
  dark 
  reacted 
  chiefly 
  for 
  

   ferric. 
  The 
  light 
  and 
  dark 
  portions 
  were 
  so 
  nearly 
  alike 
  in 
  

   specific 
  gravity 
  that 
  they 
  could 
  not 
  be 
  satisfactorily 
  separated 
  

   by 
  means 
  of 
  the 
  silver-thallium 
  nitrate 
  fusion. 
  The 
  dark 
  por- 
  

   tion 
  was 
  found 
  to 
  have 
  a 
  somewhat 
  lower 
  specific 
  gravity 
  than 
  

   the 
  light, 
  and 
  a 
  product 
  was 
  separated 
  which 
  represented 
  a 
  par- 
  

   tial 
  separation 
  of 
  the 
  two 
  minerals 
  and 
  consisted 
  chiefly 
  of 
  the 
  

   light-colored 
  material. 
  This 
  was 
  analyzed 
  by 
  Mr. 
  W. 
  E. 
  Ford 
  

   of 
  the 
  Sheffield 
  Laboratory 
  with 
  results 
  which 
  are 
  given 
  

   beyond. 
  The 
  iron 
  was 
  found 
  by 
  Ford 
  to 
  be 
  both 
  ferrous 
  and 
  

   ferric, 
  and, 
  since 
  a 
  little 
  of 
  the 
  carefully 
  selected 
  light-colored 
  

   material 
  gave 
  only 
  the 
  reactions 
  for 
  ferrous 
  iron, 
  it 
  was 
  inferred 
  

   that 
  the 
  original 
  mineral 
  was 
  undoubtedly 
  a 
  ferrous 
  compound, 
  

   and 
  that 
  the 
  dark 
  portions 
  were 
  the 
  result 
  of 
  partial 
  decompo- 
  

   sition, 
  attended 
  by 
  the 
  oxidation 
  of 
  the 
  iron 
  and 
  manganese. 
  

   Although 
  the 
  analysis 
  indicated 
  that 
  the 
  mineral 
  was 
  undoubt- 
  

   edly 
  new, 
  the 
  results, 
  owing 
  to 
  the 
  character 
  of 
  the 
  material, 
  

   were 
  not 
  wholly 
  satisfactory 
  and 
  conclusive, 
  and 
  there 
  was 
  

   some 
  doubt 
  as 
  to 
  the 
  propriety 
  of 
  giving 
  a 
  new 
  name 
  to 
  the 
  

   species. 
  

  

  