﻿124 
  

  

  limarts 
  Journal, 
  January, 
  1848.) 
  Massive 
  strontianite 
  is 
  also 
  said 
  to 
  

   have 
  been 
  found 
  by 
  Mr. 
  James 
  Heron, 
  at 
  Warwick, 
  in 
  Orange 
  county. 
  

   Dana's 
  Mineralogy, 
  2d 
  ed., 
  p. 
  254. 
  

  

  CALCAREOUS 
  SPAR. 
  

   (Mineralogy 
  of 
  New-York, 
  page 
  215.) 
  

  

  Of 
  the 
  crystallized 
  varieties 
  of 
  this 
  mineral, 
  the 
  most 
  interesting- 
  

   localities 
  which 
  have 
  heretofore 
  been 
  found, 
  perhaps, 
  in 
  any 
  part 
  of 
  the 
  

   world, 
  exist 
  in 
  this 
  State. 
  The 
  finest 
  specimens 
  have 
  been 
  obtained 
  

   at 
  the 
  mines 
  of 
  Rossie, 
  St. 
  Lawrence 
  county. 
  One 
  gigantic 
  specimen 
  

   in 
  the 
  cabinet 
  of 
  Prof. 
  B. 
  Sillirnan, 
  Jr., 
  weighs 
  165 
  pounds, 
  and 
  is 
  nearly 
  

   transparent. 
  Dana's 
  Mineralogy, 
  2d 
  ed. 
  

  

  The 
  accompanying 
  cut 
  is 
  the 
  figure 
  of 
  a 
  twin 
  from 
  Rossie, 
  in 
  the 
  col- 
  

   lection 
  of 
  Mr. 
  Alger, 
  of 
  more 
  than 
  a 
  foot 
  in 
  length. 
  Alger's 
  Phillips* 
  

   page 
  265. 
  

  

  Mr. 
  Dana 
  has 
  given 
  a 
  figure 
  of 
  a 
  crystal 
  differing 
  from 
  any 
  of 
  those 
  

   contained 
  in 
  my 
  report. 
  S€e 
  Sill. 
  Jour., 
  xlvi, 
  p. 
  33. 
  

  

  In 
  regard 
  to 
  the 
  form 
  of 
  the 
  calcareous 
  spar 
  from 
  Rossie, 
  Mr. 
  Ash- 
  

   mead 
  has 
  remarked, 
  that 
  in 
  reducing 
  specimens 
  to 
  convenient 
  size 
  for 
  

   the 
  cabinet, 
  he 
  observed 
  that 
  some 
  of 
  the 
  fractured 
  crystals 
  were 
  sus- 
  

   ceptible 
  of 
  mechanical 
  division 
  in 
  different 
  directions 
  from 
  those 
  of 
  the 
  

   planes 
  of 
  a 
  rhombohedron. 
  He 
  succeeded 
  in 
  obtaining 
  as 
  a 
  nucleus, 
  a 
  

   solid, 
  bounded 
  by 
  six 
  isosceles 
  triangular 
  planes, 
  of 
  similar 
  lustre, 
  or 
  two 
  

   obtuse, 
  three-sided 
  pyramids, 
  placed 
  base 
  to 
  base 
  ; 
  it 
  has 
  but 
  one 
  axis, 
  

   passing 
  through 
  opposite 
  solid 
  angles 
  ; 
  assuming 
  the 
  axis 
  to 
  be 
  vertical, 
  

   the 
  base 
  is 
  an 
  equilateral 
  triangle. 
  As 
  the 
  faces 
  are 
  not 
  parallel, 
  but 
  

   inclined 
  to 
  each 
  other, 
  it 
  is 
  susceptible 
  of 
  perfect 
  cleavage 
  in 
  six 
  direc- 
  

   tions. 
  

  

  " 
  The 
  solid 
  angle 
  of 
  the 
  apex 
  is 
  similar 
  to 
  the 
  obtuse 
  solid 
  angle 
  of 
  

   the 
  rhombohedron, 
  therefore, 
  by 
  truncating 
  the 
  alternate 
  solid 
  angles 
  of 
  

   the 
  rhombohedron, 
  this 
  solid 
  is 
  produced." 
  Proceedings 
  of 
  the 
  Academy 
  

   of 
  Nat. 
  Scien. 
  of 
  Phila., 
  Feb. 
  8, 
  1848. 
  

  

  