﻿448 
  Scientific 
  Intelligence. 
  

  

  Massive 
  without 
  crystal 
  or 
  cleavage 
  faces. 
  H. 
  = 
  2-5. 
  G. 
  = 
  

   1-94-1- 
  98. 
  Color 
  of 
  fresh 
  material 
  bluish 
  green, 
  changing 
  on 
  

   exposure 
  to 
  brownish 
  black. 
  Biaxial, 
  negative. 
  Large 
  optical 
  

   angle. 
  Eefractive 
  index 
  about 
  1-51. 
  Birefringence 
  near 
  that 
  of 
  

   quartz. 
  Comp. 
  — 
  Essentially 
  an 
  aluminium-ferric 
  silicate 
  with 
  

   large 
  amounts 
  of 
  water 
  (22 
  per 
  cent). 
  Loses 
  its 
  water 
  very 
  

   readily 
  without 
  destroying 
  the 
  crystal 
  structure 
  or 
  materially 
  

   altering 
  the 
  optical 
  characters. 
  Reabsorbs 
  water 
  easily. 
  Found 
  

   at 
  the 
  Highland 
  Boy 
  mine, 
  Bingham, 
  Utah, 
  in 
  irregular 
  veins 
  

   associated 
  with 
  pyrite 
  and 
  other 
  ore 
  minerals. 
  Name 
  derived 
  

   from 
  the 
  cable 
  address, 
  Racewin, 
  of 
  H. 
  V. 
  Winchell 
  who 
  first 
  

   called 
  attention 
  to 
  the 
  mineral. 
  

  

  Zebedassite. 
  A. 
  Brusoni, 
  Riv. 
  Min, 
  50, 
  74, 
  1918. 
  Ortho- 
  

   rhombic? 
  In 
  fibrous 
  aggregates. 
  H. 
  = 
  2. 
  G. 
  = 
  2194. 
  Color 
  

   white. 
  Silky 
  luster. 
  Refractive 
  indices, 
  1-51-1-53. 
  The 
  direc- 
  

   tion 
  of 
  elongation 
  of 
  the 
  fibers 
  is 
  optically 
  positive. 
  Comp. 
  — 
  

   5MgO.Al 
  2 
  3 
  .6Si0 
  2 
  .4H 
  2 
  0. 
  Infusible. 
  Ignited 
  with 
  cobalt 
  

   nitrate 
  assumes 
  a 
  rose-violet 
  color. 
  Yields 
  much 
  water 
  when 
  

   heated 
  in 
  a 
  closed 
  tube. 
  Easily 
  soluble 
  in 
  acids 
  with 
  the 
  for- 
  

   mation 
  of 
  a 
  silica 
  jelly 
  on 
  evaporation. 
  Occurs 
  filling 
  fractures 
  

   in 
  a 
  serpentine 
  rock 
  found 
  at 
  Zebedassi, 
  near 
  Volpedo, 
  Piedmont, 
  

   Italy. 
  

  

  4. 
  Kimoerley 
  Diamonds: 
  especially 
  Cleavage 
  Diamonds; 
  by 
  

   J. 
  R. 
  Sutton. 
  Trans. 
  Roy. 
  Soc, 
  So. 
  Africa, 
  7, 
  65-96, 
  1918.— 
  This 
  

   paper 
  gives 
  a 
  detailed 
  study 
  of 
  various 
  aspects 
  of 
  the 
  diamonds 
  

   obtained 
  from 
  the 
  mines 
  of 
  the 
  Kimberley 
  district. 
  Tables 
  are 
  

   presented 
  which 
  show 
  the 
  proportions 
  from 
  each 
  mine 
  of 
  the 
  

   different 
  sorts 
  of 
  diamonds 
  produced. 
  The 
  question 
  of 
  change 
  

   in 
  amount 
  and 
  character 
  of 
  the 
  diamonds 
  obtained 
  at 
  different 
  

   depths 
  in 
  the 
  various 
  mines 
  is 
  discussed. 
  In 
  regard 
  to 
  the 
  cleav- 
  

   age 
  fragments 
  that 
  are 
  so 
  commonly 
  found 
  the 
  author 
  suggests 
  

   that 
  the 
  small 
  inclusions, 
  like 
  garnet 
  and 
  zircon, 
  that 
  are 
  fre- 
  

   quently 
  found 
  in 
  the 
  diamonds, 
  may 
  be 
  one 
  of 
  the 
  important 
  

   causes 
  of 
  this 
  cleavage. 
  These 
  inclusions 
  possess 
  very 
  different 
  

   coefficients 
  of 
  expansion 
  from 
  that 
  of 
  the 
  diamond 
  and 
  when 
  the 
  

   temperature 
  changes 
  from 
  that 
  of 
  their 
  original 
  formation, 
  

   internal 
  strains 
  would 
  be 
  set 
  up, 
  which 
  might 
  very 
  well 
  cause 
  the 
  

   breaking 
  of 
  the 
  diamond 
  crystal. 
  w. 
  e. 
  f. 
  

  

  5. 
  Tear-Figures 
  on 
  Certain 
  Minerals; 
  by 
  Mikio 
  Kuhara. 
  

   Published 
  in 
  four 
  parts 
  in 
  Mem. 
  Coll. 
  Engl. 
  Kyoto 
  University, 
  

   vol. 
  1, 
  Nos. 
  8, 
  10, 
  vol. 
  2, 
  Nos. 
  2, 
  3, 
  1916-1918.— 
  By 
  "tear-figures" 
  

   the 
  author 
  means 
  the 
  figures 
  produced 
  by 
  light 
  percussion 
  or 
  

   pressure 
  from 
  a 
  needle 
  point 
  upon 
  a 
  smooth 
  crystal 
  face. 
  The 
  

   figures 
  formed 
  on 
  the 
  following 
  minerals 
  have 
  been 
  studied; 
  

   stibnite, 
  galena, 
  sphalerite, 
  pyrite, 
  vivianite, 
  enargite, 
  calcite, 
  

   gypsum, 
  barite, 
  aragonite, 
  alum, 
  borax, 
  wulfenite, 
  copper 
  sul- 
  

   phate. 
  These 
  figures 
  usually 
  have 
  the 
  shape 
  of 
  a 
  polygon 
  

   together 
  with 
  radiating 
  cracks, 
  although 
  the 
  latter 
  may 
  not 
  

  

  