﻿No. 
  30.] 
  

  

  89 
  

  

  Fig» 
  11. 
  

  

  Tig. 
  12* 
  

  

  The 
  surface 
  often 
  presents 
  a 
  columnar 
  appearance, 
  as 
  is 
  repre* 
  

   sented 
  in 
  specimen. 
  No. 
  53. 
  

  

  Besides 
  tliis 
  mineral, 
  there 
  is 
  found 
  with 
  tlie 
  micaceous 
  ore, 
  a 
  

   hard 
  silicious 
  mineral, 
  of 
  dark 
  color, 
  and 
  conchoidal 
  fracture, 
  

   (No. 
  54,) 
  a 
  porous 
  and 
  stratified 
  variety 
  of 
  tlie 
  same, 
  (No. 
  55,) 
  

   and 
  a 
  white 
  spongy 
  mass 
  (No. 
  56,) 
  apparently 
  the 
  heavy 
  spar 
  

   partially 
  decomposed 
  by 
  exposure 
  to 
  the 
  weather. 
  

  

  57. 
  Dark 
  green 
  serpentine. 
  Associated 
  with 
  the 
  rock 
  in 
  the 
  

   vicinity 
  of 
  the 
  above 
  locality. 
  

  

  The 
  iron 
  froth 
  and 
  the 
  heavy 
  spar 
  of 
  the 
  locality 
  above 
  des- 
  

   cribed, 
  appear 
  to 
  occupy 
  separate 
  veins, 
  which 
  vary 
  constantly 
  

   in 
  width, 
  and 
  change 
  in 
  character 
  v/ithin 
  short 
  distances. 
  Their 
  

   relation 
  is 
  shown 
  in 
  the 
  following 
  section 
  i 
  

  

  