﻿232 
  EEPORT 
  UNITED 
  STATES 
  GEOLOGICAL 
  SURVEY. 
  

  

  Lepidolite. 
  — 
  Station 
  17 
  of 
  1873, 
  in 
  a 
  form 
  resembling 
  the 
  Saxon 
  zinn- 
  

   waldite. 
  

  

  Leucite. 
  — 
  Table 
  Mountain, 
  Golden 
  City. 
  

  

  Lbucopyrite. 
  — 
  Spanish 
  Bar. 
  

  

  LicoEiTE. 
  — 
  North 
  Clear 
  Creek. 
  

  

  Lignite. 
  — 
  Mouth 
  of 
  Gunnison. 
  There 
  it 
  retains 
  its 
  wood 
  structure. 
  

  

  LiMONiTE. 
  — 
  Near 
  station 
  17 
  of 
  1873; 
  in 
  the 
  Tertiary 
  sandstones 
  west 
  of 
  

   Plum 
  Creek, 
  near 
  Colorado 
  City; 
  in 
  several 
  localities 
  of 
  South 
  Park. 
  

   At 
  the 
  head 
  of 
  south 
  fork 
  of 
  Anthracite 
  Creek, 
  west 
  slope 
  of 
  Sangre 
  

   de 
  Cristo 
  range, 
  above 
  Mosco 
  Pass. 
  Numerous 
  localities 
  in 
  White 
  

   Kiver 
  region. 
  The 
  "kidney-ores" 
  of 
  Lignitic 
  group. 
  

  

  Magnesite. 
  — 
  In 
  small 
  quantities 
  in 
  the 
  Running 
  lode 
  at 
  Black 
  Hawk. 
  

  

  Magnetic 
  iron. 
  — 
  Bear 
  Creek. 
  Ralston 
  Creek, 
  Grape 
  Creek. 
  

  

  Magnetite. 
  — 
  In 
  loose 
  nodules 
  on 
  Guunell 
  and 
  Procer 
  Hills, 
  at 
  Central; 
  

   in 
  small 
  octahedric 
  crystals 
  in 
  the 
  gneissic 
  rock 
  on 
  station 
  1 
  ; 
  on 
  sta- 
  

   tion 
  54 
  of 
  1873. 
  Occurring 
  in 
  the 
  granites 
  of 
  various 
  localities, 
  Silver 
  

   Hills, 
  White 
  House, 
  Capitol; 
  in 
  the 
  dolerite 
  rocks 
  generally. 
  At 
  

   Idaho 
  and 
  Caribou. 
  Mined 
  on 
  Grape 
  Creek, 
  near 
  Caiion 
  City. 
  Occurs 
  

   near 
  Golden. 
  

  

  Malachite. 
  — 
  Is 
  found 
  as 
  the 
  result 
  of 
  decomposition 
  of 
  fahlerz 
  and 
  

   other 
  minerals 
  at 
  the 
  Dallas, 
  Leavenworth, 
  and 
  other 
  mines 
  near 
  Cen- 
  

   tral; 
  at 
  the 
  No 
  Name, 
  Caribou, 
  Seven-Tliirty, 
  Fourth 
  of 
  July, 
  and 
  

   others, 
  at 
  Caribou; 
  at 
  some 
  of 
  the 
  Georgetown 
  mines; 
  at 
  the 
  Hard- 
  

   scrabble 
  mines, 
  on 
  station 
  46 
  of 
  1873, 
  and 
  other 
  localities 
  ; 
  at 
  Crater 
  

   Mountain, 
  in 
  the 
  mines 
  of 
  Fair 
  Play 
  and 
  Elk 
  Mountain 
  district. 
  Mala- 
  

   chite 
  lode, 
  Bear 
  Creek, 
  Gendhema's 
  lode, 
  Tucker's 
  Gulch, 
  Oro 
  City, 
  

   Caiion 
  City, 
  Pollock, 
  Montezuma, 
  

  

  Marcasite. 
  — 
  Philipps 
  mine, 
  Fair 
  Play. 
  

  

  Melaconite. 
  — 
  Occurring 
  at 
  the 
  Gunuell, 
  Briggs, 
  Leavitt, 
  Leavenworth, 
  

   and 
  other 
  mines, 
  near 
  Central 
  ; 
  at 
  the 
  Unknown 
  mine, 
  in 
  Montgomery. 
  

   Tucker's 
  Gulch, 
  Jefferson 
  County, 
  Colorado. 
  Pollock, 
  Mosquito. 
  

  

  Melanterite. 
  — 
  On 
  the 
  dumps 
  of 
  the 
  Wood, 
  Dallas, 
  and 
  Kansas 
  mines, 
  

   and 
  others, 
  near 
  Central; 
  in 
  the 
  Sweet 
  Home 
  Mine. 
  

  

  Mesitinite. 
  — 
  Black 
  Prince 
  lode. 
  Lump 
  Gulch. 
  

  

  Mesolite. 
  — 
  Golden, 
  Col. 
  Table 
  Mountain. 
  

  

  MispiCKEL. 
  — 
  Together 
  with 
  pyrite 
  in 
  the 
  Bobtail 
  and 
  other 
  mines. 
  

  

  Minium. 
  — 
  Freeland 
  mine. 
  Trail 
  Creek, 
  Georgetown, 
  Central 
  City. 
  

  

  Micaceous 
  iron 
  ore, 
  — 
  Caribou, 
  Ralston 
  Creek. 
  Unaweep, 
  Caiion. 
  

  

  Meteoric 
  iron. 
  — 
  Vide 
  Iron. 
  

  

  Molybdenite. 
  — 
  Leavitt 
  mine, 
  at 
  Central 
  ; 
  occurring 
  in 
  thread-like 
  

   veins 
  in 
  Silver 
  Hills, 
  near 
  Fair 
  Play, 
  Boulder 
  County. 
  

  

  Muscovite. 
  — 
  In 
  good 
  crystals 
  on 
  station 
  2 
  of 
  1873, 
  and 
  in 
  the 
  coarse- 
  

   grained 
  granite 
  near 
  Canon 
  City 
  ; 
  throughout 
  the 
  granite 
  and 
  partly 
  

   in 
  the 
  schist 
  rocks. 
  

  

  Nagyagite.— 
  Gold 
  Hill. 
  

  

  Natrolite. 
  — 
  Golden, 
  Col. 
  Table 
  Mountain. 
  

  

  Obsidian.— 
  Porphyri 
  tic, 
  in 
  a 
  dike, 
  at 
  station 
  27 
  of 
  1873 
  ; 
  Buffalo 
  Peak, 
  

   Arkansas 
  Valley, 
  and 
  Union 
  Park. 
  Under 
  the 
  trachyte, 
  on 
  Gunnison 
  

   River 
  (porphyri 
  tic 
  and 
  spherulitic). 
  

  

  Onyx. 
  — 
  Middle 
  Park. 
  

  

  Opal. 
  — 
  Idaho, 
  Aguas 
  Calientes, 
  Gilson 
  Gulch. 
  

  

  Ortiioclase. 
  — 
  In 
  crystals 
  in 
  the 
  porphyries 
  of 
  Gregory 
  Hill, 
  partly 
  

   altered 
  into 
  sanidite. 
  It 
  occurs 
  sometimes 
  in 
  very 
  large 
  pieces 
  

   throughout 
  the 
  coarse-graiued 
  granites 
  of 
  Colorado 
  ; 
  in 
  the 
  porphyry 
  

   dike 
  at 
  Gold 
  Hills, 
  crystals 
  of 
  large 
  size. 
  Jefferson 
  County, 
  Colorado, 
  

   crystallized. 
  Greeu, 
  South 
  Park, 
  west 
  of 
  Pike's 
  Peak. 
  Reddish, 
  Elk 
  

  

  