﻿342 
  Penfield 
  and 
  Warren 
  — 
  Minerals 
  from 
  Franklin^ 
  N. 
  J, 
  

   The 
  results 
  of 
  the 
  analysis 
  by 
  Warren 
  are 
  as 
  follows 
  : 
  — 
  

  

  

  

  

  Average. 
  

  

  Ratio. 
  

  

  SiO„ 
  

  

  30-99 
  

  

  

  30-99 
  

  

  •516 
  

  

  A1,0, 
  

  

  l'7-89 
  

  

  

  17-89 
  

  

  •173 
  

  

  Fe,03 
  

  

  12-30 
  

  

  12-37 
  

  

  12-33 
  

  

  •077 
  

  

  Mn.O^ 
  

  

  1-38 
  

  

  

  1-38 
  

  

  •009 
  

  

  PbO 
  

  

  18.47 
  

  

  18-59 
  

  

  18-53 
  

  

  •083 
  

  

  MnO 
  

  

  2-12 
  

  

  

  2-12 
  

  

  •029 
  

  

  M^O 
  

  

  0-52 
  

  

  

  •52 
  

  

  •013 
  

  

  CaO 
  

  

  11-50 
  

  

  

  11-50 
  

  

  •205 
  

  

  SrO 
  

  

  3-89 
  

  

  

  3-89 
  

  

  -037 
  

  

  H.0 
  

  

  1-62 
  

  

  

  1-62 
  

  

  •090 
  

  

  SiO„ 
  6 
  

  

  •259 
  R 
  0„ 
  3-00 
  

  

  L-367RO 
  4-2( 
  

  

  H„0 
  1-06 
  

  

  Partial 
  

  

  Analysis, 
  

  

  SiO, 
  

  

  30-88 
  

  

  A1.03 
  

  

  17-99 
  

  

  Fe,03 
  

  

  12-96 
  

  

  PbO 
  

  

  17-47 
  

  

  MnO 
  

  

  2^96 
  

  

  MaO 
  

  

  1^02 
  

  

  CaO 
  \ 
  

   SrO 
  \ 
  

  

  15^33 
  

  

  

  1-62 
  

  

  100^77 
  

  

  100-23 
  

  

  The 
  ratio 
  of 
  8162 
  : 
  ^fi^ 
  : 
  RO 
  : 
  H^O 
  approximates 
  closely 
  to 
  

   6:3:4:1, 
  which 
  gives 
  as 
  the 
  empirical 
  formula 
  1^^' 
  ^"\ 
  

   SiAe, 
  or 
  R%(R^^^-OH)R^^', 
  (SiO,)3. 
  The 
  general 
  formula 
  is 
  

   that 
  of 
  epidote, 
  but 
  the 
  material 
  differs 
  from 
  any 
  variety 
  of 
  

   that 
  mineral 
  previously 
  described 
  in 
  having 
  the 
  bivalent 
  metals 
  

   lead 
  and 
  strontium 
  isomorphous 
  with 
  calcium. 
  Owing 
  to 
  its 
  

   color 
  and 
  the 
  presence 
  of 
  manganese 
  sesquioxide 
  the 
  mineral 
  is 
  

   allied 
  to 
  piedmontite. 
  It 
  will 
  be 
  observed 
  that 
  the 
  quantity 
  

   of 
  protoxide, 
  RO, 
  indicated 
  by 
  the 
  analysis, 
  is 
  a 
  trifle 
  high, 
  

   SiOj 
  : 
  RO 
  being 
  6 
  : 
  4-26 
  instead 
  of 
  6 
  : 
  4, 
  as 
  it 
  should 
  be 
  to 
  sat- 
  

   isfy 
  the 
  epidote 
  formula. 
  The 
  analyses, 
  however, 
  were 
  made 
  

   with 
  very 
  great 
  care, 
  and 
  in 
  the 
  determination 
  of 
  the 
  calcium 
  

   and 
  strontium 
  the 
  separated 
  oxides 
  were 
  converted 
  into 
  sul- 
  

   phates 
  and 
  thus 
  found 
  to 
  have 
  the 
  correct 
  molecular 
  weight. 
  

   The 
  partial 
  analysis 
  given 
  was 
  made 
  on 
  material 
  taken 
  from 
  

   the 
  same 
  specimen 
  as 
  used 
  for 
  the 
  other 
  analysis, 
  but 
  the 
  higher 
  

   oxide 
  of 
  manganese 
  was 
  not 
  determined 
  and 
  strontium 
  was 
  

   not 
  separated 
  from 
  the 
  calcium. 
  

  

  In 
  its 
  chemical 
  as 
  well 
  as 
  in 
  its 
  crystal 
  lographic 
  relations, 
  

   hancockite 
  is 
  a 
  member 
  of 
  the 
  epidote 
  group 
  of 
  minerals, 
  and 
  

   should 
  occupy 
  a 
  position 
  next 
  to 
  piedmontite 
  in 
  a 
  system 
  of 
  

   mineralogy. 
  It 
  is 
  especially 
  interesting 
  on 
  account 
  of 
  the 
  con- 
  

   siderable 
  quantities 
  of 
  lead 
  and 
  strontium 
  which 
  it 
  contains, 
  

   elements 
  thus 
  far 
  observed 
  in 
  combination 
  with 
  silicic 
  acid 
  in 
  

   only 
  a 
  few 
  rare 
  mineral 
  species. 
  

  

  Before 
  the 
  blowpipe, 
  hancockite 
  fuses 
  with 
  intumescence 
  at 
  

   3 
  to 
  a 
  black, 
  slightly 
  magnetic 
  globule. 
  The 
  globule 
  becomes 
  

   more 
  strongly 
  magnetic 
  if 
  heated 
  on 
  charcoal. 
  With 
  sodium 
  

   carbonate 
  on 
  charcoal 
  a 
  coating 
  of 
  lead 
  oxide 
  is 
  obtained. 
  

   Keacts 
  for 
  manganese 
  with 
  the 
  sodium 
  carbonate 
  bead 
  in 
  O. 
  F^ 
  

   The 
  mineral 
  is 
  insoluble 
  in 
  hydrochloric 
  acid, 
  but, 
  like 
  epidote, 
  

  

  