﻿2 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL 
  MUSEUM 
  vol. 
  G7 
  

  

  Of 
  the 
  75 
  or 
  85 
  pounds 
  of 
  material 
  mentioned 
  above, 
  two 
  pieces 
  

   weighing, 
  respectively, 
  1,686 
  and 
  1.956 
  grams, 
  were 
  received 
  at 
  the 
  

   United 
  States 
  National 
  Museum, 
  and 
  it 
  is 
  upon 
  these 
  that 
  the 
  fol- 
  

   lowing 
  descriptive 
  matter 
  is 
  based. 
  

  

  Macroscopically 
  the 
  stone 
  is 
  of 
  a 
  fine 
  compact 
  texture, 
  sufficiently 
  

   firm 
  to 
  take 
  a 
  polish, 
  showing 
  on 
  a 
  sawn 
  surface 
  an 
  abundant 
  

   sprinkling 
  of 
  small 
  white 
  and 
  gray 
  chondrites 
  in 
  part 
  breaking 
  

   with 
  the 
  matrix 
  and 
  but 
  little 
  metal, 
  though 
  it 
  must 
  be 
  confessed 
  

   that 
  there 
  is 
  apparently 
  more 
  than 
  indicated 
  in 
  the 
  analysis 
  quoted 
  

   below. 
  There 
  are 
  a 
  number 
  of 
  sharp 
  black 
  veins 
  along 
  which 
  a 
  slight 
  

   movement 
  has 
  taken 
  place, 
  producing 
  slicken-sided 
  or 
  hornischflache 
  

   surfaces. 
  They 
  are 
  plainly 
  fractures 
  due 
  to 
  crushing 
  or 
  some 
  sudden 
  

   shock, 
  and 
  not 
  true 
  veins. 
  

  

  Microscopic 
  examination 
  shows 
  the 
  silicate 
  portion 
  of 
  the 
  stone 
  

   (91.415 
  per 
  cent) 
  to 
  consist 
  of 
  olivine 
  and 
  enstatite, 
  with 
  small 
  

   amounts 
  of 
  a 
  maskelynite 
  and 
  more 
  rarely 
  the 
  calcium 
  phosphate 
  

   merrillite. 
  (See 
  pi. 
  1.) 
  There 
  are 
  also 
  small 
  black 
  granules, 
  assumed 
  

   to 
  be 
  chromite. 
  Troilite 
  is 
  rather 
  abundant. 
  An 
  analysis 
  made 
  by 
  

   Dr. 
  J. 
  E. 
  Whitfield 
  for 
  the 
  Milwaukee 
  Museum, 
  which 
  I 
  am 
  per- 
  

   mitted 
  to 
  use 
  here, 
  yielded 
  : 
  

  

  Mineral 
  portion 
  91. 
  415 
  

  

  Metallic 
  portion 
  | 
  

  

  Iron 
  nickel 
  alloy 
  J 
  

  

  Troilite 
  (FeS) 
  7.590 
  

  

  100. 
  000 
  

   Composition 
  of 
  the 
  m'neral 
  portion: 
  

  

  Silica 
  (Si0 
  2 
  ) 
  45.280 
  

  

  Alumina 
  (A1 
  2 
  3 
  ) 
  3.103 
  

  

  Chromic 
  acid 
  (Cr^0 
  3 
  ) 
  0.547 
  

  

  Phosphoric 
  acid 
  (P-Oo) 
  0.284 
  

  

  Ferrous 
  oxide 
  (FeO) 
  16.484. 
  

  

  Manganese 
  oxide 
  (MnO) 
  _* 
  0.500 
  

  

  Calcium 
  oxide' 
  (CaO) 
  none 
  

  

  Magnesium 
  oxide 
  (MgO) 
  32.166 
  

  

  Nickel 
  oxide 
  (NiO) 
  0.231 
  

  

  Cobalt 
  oxide 
  (CoO) 
  0. 
  02S 
  

  

  Soda 
  (Na 
  2 
  0) 
  1.218 
  

  

  Potash 
  (K 
  2 
  0) 
  0. 
  158 
  

  

  99. 
  999 
  

  

  The 
  composition 
  of 
  the 
  metal 
  alloy 
  obtained 
  by 
  analysis 
  of 
  0.4400 
  

   grams 
  separated 
  from 
  accompanying 
  troilite 
  is 
  as 
  follows: 
  

  

  Per 
  cent 
  

  

  Iron 
  , 
  0.4025=91.4777 
  

  

  Nickel 
  0.0338= 
  7.682 
  

  

  Cobalt 
  0.0037= 
  0.841 
  

  

  