﻿228 
  KEPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  Amber 
  ? 
  — 
  (One 
  specimen 
  found 
  on 
  head 
  of 
  Cherry 
  Creek). 
  

  

  Amethyst. 
  — 
  At 
  Nevada 
  and 
  other 
  neighboring; 
  localities. 
  On 
  Eock 
  

   Creek, 
  Clear 
  Creek 
  County. 
  San 
  Juan 
  mines. 
  

  

  Amianthite. 
  — 
  North 
  Boulder 
  Creek. 
  

  

  Amphibolite. 
  — 
  Buffalo 
  Peak, 
  Montgomery. 
  In 
  small 
  acicular 
  crystals 
  

   in 
  the 
  porphyritic 
  trachytes. 
  Head 
  of 
  Ohio 
  Creek 
  in 
  volcanic 
  breccia. 
  

   Along 
  Ohio 
  Creek 
  and 
  Gunnison 
  River. 
  

  

  Anglesite. 
  — 
  Freeland 
  Mine 
  on 
  Trail 
  Creek. 
  In 
  crystals 
  at 
  the 
  Horse- 
  

   shoe 
  lead 
  mine, 
  in 
  South 
  Park. 
  

  

  Anhydrite. 
  — 
  On 
  Elk 
  Creek. 
  Crystallized 
  at 
  the 
  salt-works 
  in 
  South 
  

   Park. 
  

  

  ANTHOPHYLLiTE.~]N'orth 
  Boulder 
  Creek. 
  

  

  Anthracite. 
  — 
  Gunnison 
  River, 
  Southwest 
  Colorado. 
  Anthracite 
  Creek 
  

   O 
  Be 
  Joyful 
  Creek, 
  in 
  the 
  Elk 
  Mountains. 
  CTncompahgre 
  Canon 
  (semi- 
  

   anthracite). 
  

  

  Antimony. 
  — 
  Gold 
  Hill. 
  

  

  Antrimolite. 
  — 
  Golden, 
  Colorado 
  Table 
  Mountain. 
  

  

  Apatite. 
  — 
  At 
  Fairplay. 
  

  

  Apophyllite.— 
  Station 
  22 
  of 
  1873. 
  

  

  Aragonite. 
  — 
  Occurring 
  in 
  the 
  form 
  usually 
  termed 
  j^os/ern, 
  very 
  beau- 
  

   tifully 
  in 
  Marshal's 
  Tunnel, 
  Georgetown, 
  Golden. 
  Table 
  Mountain. 
  

  

  Argentite. 
  — 
  Colorado 
  Central 
  Mine, 
  Terrible, 
  and 
  other 
  mines 
  at 
  

   Georgetown; 
  in 
  the 
  No 
  Name, 
  Caribou, 
  and 
  others 
  at 
  Caribou; 
  in 
  some 
  

   mines 
  near 
  Nevada; 
  in 
  the 
  Senator 
  lode 
  of 
  the 
  Hardscrabble 
  mining 
  

   district; 
  it 
  occurs 
  mostly 
  in 
  small 
  quantities 
  imbedded 
  either 
  in 
  quartz 
  

   or 
  in 
  the 
  predominating 
  ore 
  ; 
  when 
  decomposed, 
  native 
  silver 
  is 
  the 
  

   result. 
  At 
  the 
  Silver 
  Star, 
  Moose, 
  and 
  other 
  mines 
  near 
  Fairplay. 
  

  

  Arsenopyrite. 
  — 
  Priest 
  mine, 
  Fairplay. 
  

  

  Arsenopyrite. 
  — 
  (With 
  silver 
  and 
  copper,) 
  Park 
  Lode, 
  Bergen's 
  Ranch, 
  

   Jefferson 
  County, 
  Colorado. 
  

  

  Asbestos. 
  — 
  occurs 
  in 
  small 
  quantities, 
  partly 
  radiated, 
  near 
  Caribou. 
  

  

  Asphalt 
  is 
  found 
  in 
  the 
  White 
  River 
  region. 
  It 
  occurs 
  in 
  veins, 
  is 
  very 
  

   compact 
  and 
  brittle. 
  Occurs 
  in 
  springs 
  near 
  the 
  summit 
  of 
  the 
  Book 
  

   Cliffs 
  ; 
  Caiion 
  City. 
  (Loew.) 
  

  

  AVENTURINE 
  FELDSPAR.— 
  On 
  Elk 
  Creek, 
  Jefferson 
  County, 
  Colorado 
  

   Territory. 
  

  

  AVENTURINE 
  QuARTZ. 
  — 
  Elk 
  Creek. 
  

  

  AzuRiTE. 
  — 
  In 
  the 
  No 
  Name, 
  together 
  with 
  malachite, 
  the 
  result 
  of 
  

   decomposition 
  of 
  fahlerz. 
  Caribou 
  ; 
  in 
  the 
  Rosita 
  mines 
  in 
  Hardscrab- 
  

   ble, 
  on 
  Trail 
  Creek, 
  on 
  Crater 
  Mountains, 
  in 
  the 
  mines 
  around 
  Fair- 
  

   play, 
  and 
  in 
  the 
  mines 
  of 
  Elk 
  Mountain 
  district, 
  Malachite 
  lode, 
  Bear 
  

   Creek, 
  Gendhemas 
  lode, 
  Tucker's 
  Gulch. 
  

  

  Barite. 
  — 
  In 
  yellow 
  tabular 
  crystals, 
  clear 
  in 
  the 
  Tenth 
  Legion 
  mine 
  of 
  

   Empire, 
  in 
  the 
  Terrible 
  mine, 
  near 
  station 
  17 
  of 
  1373, 
  and 
  on 
  station 
  46 
  

   of 
  1873; 
  near 
  Caiion 
  City, 
  transparent 
  crystals 
  occur 
  in 
  the 
  arenaceous 
  

   formations 
  of 
  that 
  locality. 
  In 
  Gilson 
  Gulch, 
  Georgetown. 
  Crystals 
  

   occur 
  in 
  the 
  limestones 
  around 
  Fairplay, 
  Apishpa 
  River, 
  Colorado. 
  

   (Amorphous). 
  White, 
  red, 
  brown. 
  Clear 
  Creek 
  Caiion. 
  Montezuma. 
  

  

  Basanite.— 
  East 
  of 
  the 
  salt 
  works 
  in 
  South 
  Park. 
  

  

  Beryl. 
  — 
  On 
  Bear 
  Creek, 
  Tiifany's 
  Ranch. 
  Stone 
  Dam, 
  Jefferson 
  County, 
  

   Colorado. 
  

  

  BiOTiTE.— 
  On 
  Buffalo 
  Peak 
  and 
  station 
  64 
  of 
  1873. 
  

  

  Bismuth,— 
  French 
  Gulch. 
  

  

  BiSMUTHiTE. 
  — 
  In 
  the 
  Las 
  Aminas 
  mine, 
  pseudomorphous. 
  

  

  Bismutite. 
  — 
  From 
  the 
  Las 
  Animas 
  mine. 
  

  

  