﻿FEB. 
  4, 
  1922 
  

  

  ERIckson: 
  tschermigite 
  

  

  51 
  

  

  quantitative 
  analyses 
  were 
  made 
  on 
  a 
  uniform 
  sample 
  of 
  carefully 
  se- 
  

   lected 
  material 
  which 
  was 
  practically 
  free 
  from 
  associated 
  mineral 
  

   and 
  gangue. 
  

  

  The 
  average 
  results 
  obtained 
  are 
  tabulated 
  below 
  (I) 
  , 
  together 
  with 
  

   the 
  theoretical 
  composition 
  of 
  ammonium 
  alum 
  [AI2 
  (804)3- 
  (NH4)2S04.- 
  

   24H2O] 
  (II), 
  and 
  analyses 
  of 
  the 
  mineral 
  from 
  Bohemia 
  (III, 
  IV). 
  

  

  TABLE 
  1. 
  — 
  Analyses 
  of 
  Tschermigite 
  

  

  ** 
  Given 
  as 
  3.83 
  per 
  cent 
  (NH4)20, 
  but 
  obviously 
  an 
  error, 
  the 
  3.83 
  per 
  cent 
  representing 
  

   NH3. 
  The 
  value 
  has 
  been 
  changed 
  to 
  its 
  equivalent 
  (5.86) 
  for 
  (NH4)20. 
  The 
  water 
  con- 
  

   tent 
  given 
  as 
  49 
  .72 
  has 
  been 
  correspondingly 
  corrected 
  to 
  47 
  .69. 
  

  

  ^ 
  Given 
  as 
  3.67 
  per 
  cent 
  NH3 
  which 
  has 
  also 
  been 
  changed 
  to 
  its 
  equivalent 
  value 
  of 
  

   5.62 
  per 
  cent 
  (NH4)20. 
  A 
  correction 
  has 
  likewise 
  been 
  made 
  of 
  the 
  reported 
  water 
  per- 
  

   centage, 
  49.54 
  obtained 
  by 
  difference, 
  to 
  47.59 
  per 
  cent. 
  

  

  ' 
  FeaOs. 
  

  

  Analysis 
  III; 
  Deichmiiller, 
  J. 
  V., 
  Neues 
  Vorkommenvon 
  Ammonium-alaun. 
  Sitzb. 
  d. 
  n. 
  

   Ges. 
  Isis, 
  Dresden, 
  1885, 
  33. 
  Analysis 
  by 
  Geissler. 
  Locality, 
  Vertrau 
  auf 
  Gott 
  mine 
  

   near 
  Dux, 
  Bohemia. 
  This 
  occurrence 
  is 
  also 
  described 
  by 
  Cornu, 
  F., 
  Tschermigite 
  von 
  

   Schellenken 
  bei 
  Dux 
  in 
  Bohmen. 
  Centr. 
  Min. 
  Geol. 
  1907, 
  467-468. 
  

  

  Analysis 
  IV; 
  Sachs, 
  A., 
  Uber 
  ein 
  neues 
  Tschermigitvorkommen 
  von 
  Briix 
  in 
  Bohmen, 
  

   etc. 
  Centr. 
  Min. 
  Geol. 
  1907: 
  465-467. 
  Locality, 
  Guidoschacht 
  in 
  Nieder-Georgental 
  

   near 
  Briix, 
  Bohemia. 
  

  

  A 
  set 
  of 
  four 
  earher 
  analyses, 
  by 
  Gruner, 
  Pfaff, 
  Lampadius, 
  and 
  

   Stromeyer, 
  showing 
  similar 
  results, 
  are 
  given 
  by 
  Rammelsberg, 
  in 
  his 
  

   Handbuch 
  d. 
  Mineralchemie, 
  p. 
  285 
  (1860). 
  Natural 
  ammonium 
  alum 
  

   also 
  occurs 
  at 
  Tschermig, 
  Bohemia 
  (from 
  which 
  place 
  the 
  mineral 
  is 
  

   named); 
  and 
  has 
  been 
  reported 
  from 
  Tokod 
  near 
  Grau, 
  Hungary; 
  

   Saalfeld 
  in 
  Thuringia; 
  in 
  crater 
  of 
  Mt. 
  Etna 
  with 
  other 
  sulfates; 
  

   and 
  at 
  Solfatara 
  at 
  Pozzuoli. 
  

  

  