﻿8 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  terms 
  and 
  definitions 
  ; 
  varieties 
  of 
  rocks 
  ; 
  conditions 
  of 
  rock 
  forma- 
  

   tion; 
  appearance 
  due 
  to 
  formation; 
  and 
  the 
  formation 
  of 
  topography. 
  

   Specimens, 
  photographs, 
  models, 
  and 
  cross-references 
  to 
  othei' 
  

   collections, 
  will 
  be 
  used 
  in 
  illustration. 
  As 
  such 
  an 
  exhibition 
  is 
  a 
  

   rarity 
  in 
  American 
  museums, 
  and 
  as 
  it 
  would 
  be 
  of 
  great 
  value 
  to 
  

   teachers 
  having 
  students 
  beginning 
  the 
  study 
  of 
  geology, 
  as 
  well 
  as 
  

   to 
  intelligent 
  visitors 
  who 
  desire 
  a 
  little 
  insight 
  into 
  this 
  subject, 
  this 
  

   collection 
  should 
  receive 
  much 
  more 
  time 
  and 
  attention 
  than 
  can 
  be 
  

   given 
  to 
  it 
  under 
  present 
  conditions. 
  As 
  far 
  as 
  carried 
  out 
  the 
  col- 
  

   lection 
  has 
  been 
  arranged 
  according 
  to 
  the 
  following 
  preliminary 
  

   scheme 
  : 
  

  

  I 
  Rock-forming 
  Minerals 
  

  

  A 
  Primary 
  minerals 
  which 
  mingle 
  with 
  others 
  to 
  form 
  rock 
  

  

  masses 
  

   B 
  Minerals 
  which 
  form 
  entire 
  rock 
  masses 
  

   C 
  Common, 
  but 
  accessory 
  minerals 
  

   D 
  Minerals 
  derived 
  from 
  others 
  by 
  alteration 
  

  

  1 
  Remaining 
  in 
  situ 
  

  

  2 
  Transported 
  to 
  a 
  distance 
  

  

  E 
  Vein-forming 
  minerals 
  

  

  II 
  Rocks 
  

  

  A 
  Classification 
  of 
  rocks 
  

   I 
  Sedimentary 
  rocks 
  

  

  I 
  a 
  Fragmental 
  rocks 
  

  

  i 
  Formed 
  by 
  weathering 
  and 
  erosion. 
  In 
  paral- 
  

   lel 
  series 
  are 
  shown 
  the 
  unconsolidated 
  and 
  

   the 
  consolidated, 
  as 
  gravel, 
  conglomerate; 
  

   sand, 
  sandstone; 
  clay, 
  shale, 
  etc. 
  

  

  ii 
  Volcanic, 
  fragmental 
  

  

  iii 
  Organic 
  fragmental 
  

   calcareous 
  

   siliceous 
  

   carbonaceous 
  

   ferruginous 
  

   phosphatic 
  

  

  