﻿346 
  Posnjah 
  and 
  Merwin 
  — 
  Hydrated 
  Ferric 
  Oxides. 
  

  

  A 
  second 
  analyzed 
  specimen 
  from 
  the 
  same 
  locality 
  con- 
  

   sisted 
  of 
  scales 
  set 
  edgewise 
  and 
  closely 
  aggregated, 
  on 
  

   fibrous 
  goethite. 
  

  

  Rossbach, 
  Germany. 
  — 
  Scattered 
  erect 
  red 
  scales 
  

   attached 
  on 
  base 
  to 
  fibrous 
  goethite, 
  or 
  in 
  loose 
  rosettes. 
  

   The 
  bounding 
  edges 
  correspond 
  to 
  forms 
  J 
  102}, 
  J001J, 
  

   1 
  100}, 
  but 
  the 
  outlines 
  are 
  usually 
  considerably 
  rounded. 
  

   Fig. 
  1. 
  

  

  Miisen, 
  Germany. 
  — 
  y(Na) 
  slightly 
  >2-50. 
  Like 
  Ross- 
  

   bach 
  but 
  { 
  103 
  } 
  is 
  a 
  prominent 
  bounding 
  form 
  or 
  edge. 
  

   £(Na)= 
  or 
  <2-20. 
  Absorption 
  for 
  y 
  increases 
  rapidly 
  

   from 
  570 
  to 
  530/*/* 
  and 
  beyond, 
  and 
  from 
  640 
  to 
  beyond 
  

   750/*/*; 
  for 
  p 
  absorption 
  is 
  nearly 
  constant 
  between 
  750 
  

   and 
  560/*/* 
  and 
  this 
  increases 
  rapidly 
  to 
  520/*/* 
  and 
  beyond 
  ; 
  

   for 
  a 
  no 
  appreciable 
  absorption 
  except 
  in 
  blue 
  and 
  violet. 
  

  

  Siegen, 
  Germany. 
  — 
  Compact 
  aggregates 
  of 
  scales 
  upon 
  

   and 
  under 
  turgite. 
  y 
  near 
  2-51. 
  

  

  N. 
  M. 
  14118, 
  near 
  Lake 
  Superior, 
  Michigan. 
  — 
  Called 
  

   goethite; 
  closely 
  aggregated 
  erect 
  scales 
  in 
  a 
  layer 
  on 
  

   fibrous 
  goethite. 
  y(Na)=2-51 
  5 
  , 
  a(Na)- 
  1-941, 
  a(Li)— 
  

   l-92 
  2 
  . 
  Scales 
  of 
  such 
  thickness 
  that 
  p 
  = 
  8~k 
  (Ridgway's 
  

   colors) 
  have 
  y 
  = 
  7n-9n; 
  also 
  p 
  — 
  15i 
  and 
  y 
  = 
  14ft 
  ; 
  also 
  

   p 
  = 
  23h 
  and 
  y 
  = 
  23h 
  to 
  i. 
  

  

  R. 
  C. 
  1489, 
  Iron 
  Mountain 
  Mine, 
  California. 
  — 
  Bladed 
  to 
  

   fibrous 
  lepidocrocite 
  lining 
  a 
  vug 
  containing 
  residual 
  sul- 
  

   phides, 
  on 
  fibrous 
  goethite 
  and 
  turgite 
  ; 
  a 
  = 
  1-92. 
  

  

  TURGITE. 
  61 
  

  

  Turgite, 
  New 
  York, 
  62 
  No. 
  18330.— 
  a(Na) 
  =2-58, 
  £(Li 
  

   and 
  y 
  (Li) 
  =2-55; 
  elongation 
  of 
  splinters 
  negative, 
  

   o(IA)=246. 
  

  

  No. 
  65269. 
  62 
  — 
  Refractive 
  indices 
  variable 
  but 
  about 
  

   a 
  (Na)=2-56, 
  P(Li) 
  and 
  y(Li) 
  about 
  2-52; 
  elongation 
  

   negative. 
  a(Li)=2-43. 
  

  

  Legal 
  Tendre 
  Hill, 
  New 
  Mexico. 
  No. 
  48228.— 
  Breaks 
  

   irregularly 
  and 
  contains 
  cavities 
  (large 
  and 
  small) 
  ; 
  

   extinguishes 
  very 
  obliquely; 
  refractive 
  indices 
  like 
  No. 
  

   18330. 
  Probably 
  pseudomorphic 
  after 
  some 
  fibrous 
  min- 
  

   eral 
  having 
  oblique 
  extinction. 
  

  

  Rockingham 
  County, 
  Virginia. 
  62 
  No. 
  17968. 
  — 
  a(Na) 
  

   = 
  2-46, 
  a(Li)=2-38, 
  elongation 
  negative. 
  

  

  Germany, 
  62 
  ' 
  ' 
  Hematite. 
  ? 
  ' 
  — 
  Fibrous, 
  elongation 
  posi- 
  

  

  ■ 
  Roe 
  p. 
  ?>2?>. 
  

  

  62 
  Analyzed, 
  Table 
  I. 
  

  

  