﻿A. 
  P. 
  lioness 
  — 
  Etching 
  Figures 
  of 
  Beryl. 
  223 
  

  

  Art. 
  XX. 
  — 
  On 
  the 
  Etching 
  Figures 
  of 
  Beryl 
  ; 
  by 
  Arthur 
  

  

  P. 
  Honess. 
  

  

  This 
  paper 
  embodies 
  a 
  brief 
  discussion 
  of 
  the 
  etch 
  figures 
  of 
  

   beryl, 
  both 
  artificial 
  and 
  natural. 
  It 
  was 
  the 
  desire 
  of 
  the 
  

   writer, 
  in 
  beginning 
  this 
  work, 
  to 
  etch 
  all 
  of 
  the 
  fundamental 
  

   forms, 
  but, 
  owing 
  to 
  the 
  fact 
  that 
  the 
  rarer 
  faces 
  occurring 
  on 
  

   the 
  available 
  material 
  were 
  so 
  slightly 
  developed 
  or 
  corroded 
  

   this 
  could 
  not 
  be 
  accomplished. 
  It 
  is 
  hoped, 
  however, 
  that, 
  in 
  

   the 
  future, 
  these 
  less 
  common 
  forms 
  may 
  be 
  obtained 
  and 
  the 
  

   etchings 
  described 
  and 
  illustrated 
  in 
  one 
  of 
  the 
  subsequent 
  

   papers, 
  the 
  contents 
  of 
  which 
  will 
  embody 
  the 
  results 
  of 
  the 
  

   writer's 
  work 
  on 
  other 
  crystal 
  types. 
  

  

  Perhaps 
  one 
  of 
  the 
  most 
  interesting 
  minerals 
  studied, 
  in 
  

   connection 
  with 
  investigation 
  of 
  natural 
  and 
  artificial 
  etch 
  fig- 
  

   ures, 
  is 
  the 
  holohedral 
  mineral 
  beryl. 
  It 
  has 
  been 
  described 
  

   from 
  various 
  localities 
  and 
  a 
  variety 
  of 
  etch 
  forms 
  discovered, 
  

   which 
  serve 
  conclusively 
  to 
  illustrate 
  the 
  holohedral 
  character 
  

   of 
  the 
  mineral. 
  W. 
  Peterson* 
  has 
  described 
  the 
  natural 
  figures 
  

   on 
  beryl 
  from 
  Mnrsinka, 
  the 
  prism 
  etchings 
  of 
  which 
  are 
  rhom- 
  

   bic 
  and 
  hexagonal 
  forms 
  with 
  the 
  longer 
  axis 
  at 
  right 
  angles 
  

   to 
  the 
  vertical 
  axis, 
  c. 
  These 
  forms 
  are 
  similar 
  to 
  those 
  

   described 
  on 
  one 
  of 
  the 
  Miask 
  crystals 
  by 
  the 
  writer. 
  On 
  the 
  

   second-order 
  pyramid 
  Peterson 
  observed 
  deep 
  and 
  shallow 
  

   rhombic 
  and 
  hexagonal 
  forms, 
  while 
  those 
  on 
  the 
  first 
  order 
  

   pyramid_were 
  triangular_with 
  their 
  edges 
  parallel 
  to 
  the 
  edges 
  

   0001/1011 
  and 
  1011/1121. 
  The 
  base 
  was 
  covered 
  with 
  regu- 
  

   lar 
  hexagonal 
  pits. 
  Carl 
  Vrba,f 
  by 
  means 
  of 
  casts, 
  was 
  able 
  to 
  

   measure 
  the 
  angles 
  of 
  the 
  etching 
  faces 
  on 
  beryl 
  from 
  Pisek 
  

   and 
  to 
  identify 
  them 
  with 
  known 
  forms. 
  A. 
  Krejci,J 
  in 
  

   his 
  study 
  of 
  the 
  beryl 
  crystals 
  from_ 
  the 
  Pisek 
  State 
  Museum, 
  

   likewise 
  identified 
  several 
  forms, 
  4011 
  — 
  2021 
  on 
  the 
  negative 
  

   pyramid. 
  P. 
  J. 
  Wiik§ 
  has 
  described 
  rectangular 
  forms 
  from 
  

   the 
  beryl 
  crystals 
  from 
  the 
  Urals. 
  A. 
  Arzruni|| 
  described 
  

   natural 
  etchings 
  on 
  crystals 
  from 
  Mursinka 
  similar 
  to 
  Peter- 
  

   son's. 
  S. 
  L. 
  Penfield,^f 
  in 
  his 
  study 
  of 
  beryl 
  from 
  Williman- 
  

   tic, 
  Conn., 
  attributes 
  the 
  origin 
  of 
  certain 
  crystals 
  showing 
  

   rare 
  faces 
  to 
  the 
  etching 
  process 
  alone. 
  

  

  Hans 
  Kohlmann,** 
  w 
  T 
  orking 
  on 
  Brazilian 
  beryl 
  crystals, 
  

   belonging 
  to 
  the 
  collections 
  of 
  Giesen 
  Mineralogical 
  Institute 
  

  

  * 
  W. 
  Peterson, 
  Bib. 
  Svensk. 
  Vet. 
  Akad. 
  Handl., 
  xv, 
  II, 
  No. 
  1, 
  1, 
  1889. 
  

  

  f 
  Zs. 
  Ki\, 
  xxiv, 
  104, 
  1894. 
  JZs. 
  Kr., 
  xxxix, 
  399, 
  1904. 
  

  

  §F. 
  J. 
  Wiik, 
  Finsk. 
  Vet. 
  Soc. 
  Fork., 
  xxvii, 
  1885. 
  

  

  I 
  A. 
  Arzruni, 
  Verb. 
  K. 
  Kuss. 
  Min. 
  Ges. 
  (2), 
  xxxi, 
  155, 
  1894. 
  

  

  If 
  S. 
  L. 
  Penfield, 
  tkis 
  Journal, 
  xxxvi, 
  317, 
  1888 
  ; 
  xl, 
  488, 
  1890. 
  

  

  **Koblmann, 
  Jb. 
  Min. 
  Beil., 
  xxv, 
  135, 
  1908. 
  

  

  Am. 
  Jour. 
  Sci. 
  — 
  Fourth 
  Series, 
  Vol. 
  XLIII, 
  No. 
  255. 
  — 
  March, 
  1917. 
  

   16 
  

  

  