﻿F. 
  W. 
  Clarice 
  — 
  Constitution 
  of 
  Melilite 
  and 
  Gehlenite. 
  481 
  

  

  With 
  these 
  formulae 
  the 
  two 
  minerals 
  become 
  similar 
  in 
  struc- 
  

   ture, 
  and, 
  as 
  will 
  be 
  shown 
  later, 
  simply 
  related 
  to 
  many 
  other 
  

   species. 
  As 
  for 
  natural 
  gehlenite, 
  its 
  analyses 
  are 
  easily 
  re- 
  

   ducible 
  to 
  mixtures 
  of 
  the 
  two 
  silicates 
  just 
  given, 
  with 
  sarco- 
  

   lite. 
  In 
  fnggerite 
  a 
  little 
  soda 
  sarcolite 
  also 
  appears. 
  

  

  Analyses 
  of 
  gehlenite. 
  

  

  

  1. 
  

  

  Damon 
  r 
  

  

  analyst. 
  

  

  From 
  

  

  Monzoni, 
  

  

  Tyrol. 
  

  

  

  

  2. 
  

  

  Lemberg 
  

  

  a 
  

  

  a 
  

  

  a 
  

  

  U 
  

  

  

  

  3. 
  

  

  Rammelsb( 
  

  

  ;rg 
  " 
  

  

  a 
  

  

  u 
  

  

  a 
  

  

  

  

  4. 
  

  

  Jan 
  ov 
  sky 
  

  

  a 
  

  

  Orowitza, 
  Ban 
  at 
  

  

  

  

  

  5. 
  

  

  Allen 
  

  

  it 
  

  

  Velard< 
  

  

  ma 
  mining 
  

  

  district, 
  Me 
  

  

  xico.* 
  

  

  

  6. 
  

  

  Mayr 
  

  

  a 
  

  

  Monzoni. 
  Fnggerite.f 
  

  

  

  

  

  1 
  

  

  2 
  

  

  3 
  

  

  4 
  

  

  5 
  

  

  6 
  

  

  Si0 
  2 
  

  

  

  31-60 
  

  

  30-01 
  

  

  29-78 
  

  

  30-73 
  

  

  26-33 
  

  

  34*04 
  

  

  Ti0 
  2 
  

  

  

  

  

  _ 
  

  

  

  

  • 
  .. 
  -. 
  - 
  

  

  •03 
  

  

  

  

  AlA 
  

  

  

  19'bO 
  

  

  21-33 
  

  

  22-02 
  

  

  22-24 
  

  

  27-82 
  

  

  17-97 
  

  

  Fe,0 
  3 
  

  

  

  5-97 
  

  

  3-56 
  

  

  3-22 
  

  

  •41 
  

  

  1-43 
  

  

  3-49 
  

  

  FeO 
  

  

  

  - 
  - 
  - 
  — 
  

  

  - 
  _ 
  _ 
  . 
  

  

  1/63 
  

  

  3-01 
  

  

  •50 
  

  

  „ 
  _ 
  . 
  _ 
  

  

  MnO 
  

  

  

  _ 
  _ 
  

  

  - 
  — 
  _ 
  - 
  

  

  •19 
  

  

  

  

  •01 
  

  

  trace 
  

  

  MgO 
  

  

  

  2-20 
  

  

  3-77 
  

  

  3-88 
  

  

  6-10 
  

  

  2-44 
  

  

  4-99 
  

  

  OaO 
  

  

  

  38-11 
  

  

  36-74 
  

  

  37-90 
  

  

  37-93 
  

  

  39-55 
  

  

  37-65 
  

  

  Na„0 
  

  

  

  •33 
  

  

  _ 
  _ 
  _ 
  _ 
  

  

  

  

  - 
  - 
  - 
  - 
  

  

  •21 
  

  

  2-04 
  

  

  K 
  2 
  

  

  

  . 
  _ 
  « 
  _ 
  

  

  . 
  _ 
  . 
  - 
  

  

  ™ 
  _ 
  -. 
  - 
  

  

  - 
  — 
  — 
  - 
  

  

  •10 
  

  

  trace 
  

  

  H 
  2 
  

  

  

  _ 
  _ 
  _ 
  _ 
  

  

  - 
  _ 
  _ 
  . 
  

  

  

  

  

  

  1-85 
  

  

  « 
  _ 
  — 
  - 
  

  

  Ign. 
  

  

  

  1-53 
  

  

  4'72 
  

  

  [1-38] 
  

  

  •37 
  

  

  - 
  _ 
  . 
  . 
  

  

  

  

  In 
  sol 
  u 
  

  

  ble 
  

  

  

  

  

  

  

  

  

  

  •12 
  

  

  99'54 
  100-13 
  

  

  100-00 
  100-79 
  

  

  100-27 
  100*20 
  

  

  The 
  iron 
  oxides 
  in 
  the 
  Mexican 
  gehlenite 
  are 
  due 
  to 
  inclu- 
  

   sions 
  of 
  magnetite, 
  and 
  should 
  therefore 
  be 
  rejected. 
  With 
  

   this 
  qualification 
  the 
  reduced 
  analyses 
  are 
  as 
  follows 
  : 
  

  

  Si0 
  2 
  

   AlA 
  

   CaO 
  

   Na 
  2 
  

  

  Reduced 
  analyses 
  of 
  gehlenite. 
  

  

  l 
  2 
  

  

  33-03 
  31-36 
  

  

  23-61 
  24-73 
  

  

  43-36 
  43-91 
  

  

  3 
  

  

  4 
  

  

  5 
  

  

  6 
  

  

  30-52 
  

  

  30-10 
  

  

  27-06 
  

  

  33-65 
  

  

  23-64 
  

  

  22-08 
  

  

  28-56 
  

  

  20-35 
  

  

  45-84 
  

  

  47-82 
  

  

  44-38 
  

  

  43-98 
  

  

  

  

  

  

  -- 
  - 
  

  

  2-02 
  

  

  100-00 
  100-00 
  100-00 
  100-00 
  100-00 
  

  

  100-00 
  

  

  * 
  See 
  Wright, 
  this 
  Journal 
  (4), 
  xxvi, 
  575, 
  1908. 
  

  

  f 
  See 
  Weinschenk, 
  Zeitschr. 
  Kryst 
  , 
  xxvii, 
  577, 
  1896. 
  The 
  other 
  analyses 
  

   are 
  from 
  Dana's 
  System 
  of 
  Mineralogy. 
  

  

  