﻿Loughlin 
  and 
  Schaller 
  — 
  Crandallite, 
  a 
  New 
  Mineral. 
  73 
  

  

  In 
  an 
  earlier 
  paper 
  it 
  was 
  suggested* 
  that 
  gorceixite 
  was 
  the 
  

   barium 
  equivalent 
  of 
  goyazite 
  (hamlinite) 
  and 
  that 
  its 
  formula 
  

   should 
  be 
  written 
  2Ba0.3A] 
  2 
  3 
  .2P 
  2 
  5 
  .7H 
  2 
  0. 
  The 
  original 
  

   anatysis 
  gives 
  ratios 
  which 
  do 
  not 
  support 
  this 
  suggestion 
  but 
  

   lead 
  to 
  the 
  formula 
  Ba0.2Al 
  2 
  3 
  .P 
  2 
  5 
  .5H 
  2 
  0. 
  Thin 
  sections 
  

   of 
  gorceixite 
  are 
  stated 
  to 
  have 
  shown 
  an 
  aggregate 
  of 
  minute, 
  

   colorless, 
  irregular 
  grains, 
  therefore, 
  apparently 
  not 
  fibrous. 
  

   The 
  question 
  thus 
  arises 
  : 
  What 
  is 
  the 
  systematic 
  position 
  of 
  

   gorceixite 
  ? 
  Does 
  it 
  belong 
  in 
  the 
  alunite-beudantite 
  group 
  

   with 
  goyazite 
  (hamlinite), 
  plumbogummite, 
  and 
  florencite, 
  

   and 
  would 
  another 
  analysis 
  on 
  pure 
  material 
  agree 
  better 
  

   with 
  the 
  type 
  formula, 
  2K0.3 
  A1 
  2 
  3 
  .2P 
  2 
  5 
  .7H 
  2 
  ; 
  or 
  is 
  gorceix- 
  

   ite, 
  with 
  the 
  formula 
  Ba0.2Al 
  2 
  3 
  .P 
  2 
  5 
  .5H 
  2 
  0, 
  a 
  fibrous 
  altera- 
  

   tion 
  product 
  of 
  a 
  pre-existing 
  unknown 
  mineral 
  of 
  the 
  goyazite 
  

   type 
  of 
  formula 
  ; 
  or 
  is 
  gorceixite 
  a 
  non-fibrous 
  mineral, 
  with 
  

   the 
  formula 
  Ba0.2Al 
  2 
  3 
  .P 
  2 
  5 
  .5H 
  2 
  0, 
  as 
  independent 
  genetically 
  

   as 
  goyazite 
  and 
  not 
  a 
  fibrous 
  alteration 
  product 
  of 
  some 
  pre- 
  

   existing 
  mineral 
  of 
  a 
  similar 
  chemical 
  composition 
  ? 
  

  

  The 
  formulas 
  of 
  goyazite 
  and 
  gorceixite 
  have 
  been 
  discussed 
  

   by 
  Farringtonf 
  in 
  a 
  recent 
  paper. 
  The 
  three 
  analyses 
  (by 
  H. 
  

   "W. 
  Nichols) 
  of 
  Brazilian 
  favas 
  given 
  by 
  Farrington 
  represent 
  

   well 
  the 
  composition 
  of 
  the 
  favas 
  but 
  are 
  of 
  no 
  value 
  for 
  the 
  

   elucidation 
  of 
  the 
  composition 
  of 
  any 
  mineral. 
  His 
  material 
  

   was 
  not 
  examined 
  optically 
  to 
  see 
  if 
  it 
  was 
  homogeneous 
  or 
  

   free 
  from 
  impurities. 
  The 
  analysis 
  of 
  Fava 
  No. 
  2 
  baffled 
  

   interpretation 
  so 
  that 
  Farrington 
  concluded 
  that 
  " 
  this 
  fava 
  

   was 
  evidently 
  a 
  mixture." 
  Of 
  Fava 
  No. 
  3 
  he 
  finally 
  states 
  : 
  

   ' 
  ; 
  Of 
  its 
  optical 
  properties 
  nothing 
  can 
  be 
  stated 
  since, 
  unfortu- 
  

   nately, 
  all 
  the 
  substance 
  of 
  the 
  fava 
  was 
  used 
  for 
  the 
  chemical 
  

   analysis." 
  

  

  The 
  homogeneity 
  and 
  character 
  of 
  transparent 
  minerals 
  can 
  

   be 
  so 
  easily 
  and 
  quickly 
  determined 
  by 
  the 
  present 
  day 
  facil- 
  

   ities 
  for 
  microscopic 
  examination 
  (imbedding 
  in 
  oils 
  of 
  known 
  

   index) 
  that 
  it 
  is 
  a 
  matter 
  of 
  regret 
  that 
  mineralogical 
  papers 
  

   are 
  still 
  published 
  with 
  detailed 
  and 
  careful 
  chemical 
  analyses 
  

   of 
  material 
  which 
  has 
  not 
  been 
  first 
  submitted 
  to 
  microscopic 
  

   examination. 
  

  

  The 
  fibrous 
  plumbogummite, 
  described 
  by 
  LacroixJ 
  (hitch- 
  

   cockite 
  ? 
  ), 
  may 
  represent 
  a 
  distinct 
  species 
  related 
  to 
  plumbo- 
  

   gummite 
  as 
  crandallite 
  is 
  to 
  goyazite. 
  

   A 
  sulphate 
  mineral 
  possibly 
  related 
  to 
  crandallite 
  was 
  described 
  

  

  * 
  Schaller, 
  W. 
  T., 
  The 
  alunite-beudantite 
  group, 
  this 
  Journal, 
  (3), 
  xxxii, 
  

   359, 
  1911. 
  In 
  Mineralogical 
  Notes, 
  Series 
  2, 
  U. 
  S. 
  Geol. 
  Survey, 
  Bull. 
  509, 
  

   p. 
  76, 
  1912. 
  

  

  f 
  Farrington, 
  O. 
  C, 
  Studies 
  of 
  Brazilian 
  favas, 
  this 
  Journal, 
  (4"), 
  xli, 
  355, 
  

   1916. 
  

  

  % 
  Lacroix, 
  A., 
  Mineralogie 
  de 
  la 
  France, 
  vol. 
  IV, 
  p. 
  586, 
  1910. 
  

  

  