﻿1864.] 
  

  

  BLAKE 
  NEVADA 
  TERRITORY. 
  

  

  Fig. 
  4. 
  — 
  Section 
  of 
  the 
  Comstock 
  Lode. 
  

  

  325 
  

  

  w. 
  

  

  It 
  is 
  divided 
  into 
  two 
  portions 
  at 
  the 
  level 
  by 
  a 
  porphyritic 
  mass, 
  

   or 
  "horse," 
  which 
  will 
  probably 
  thin 
  out 
  in 
  depth, 
  and 
  the 
  two 
  

   parts 
  of 
  the 
  vein 
  will 
  then 
  become 
  united 
  in 
  one. 
  The 
  walls 
  on 
  

   each 
  side 
  are 
  compact 
  porphyry 
  of 
  an 
  olive 
  or 
  greyish 
  -green 
  colour, 
  

   mottled 
  with 
  white, 
  and 
  charged 
  in 
  many 
  places 
  with 
  iron-pyrites. 
  

   The 
  eastern 
  part 
  of 
  the 
  vein, 
  which, 
  for 
  the 
  past 
  year, 
  has 
  been 
  

   most 
  worked, 
  is 
  30 
  feet 
  wide 
  at 
  the 
  lower 
  level, 
  and 
  consists 
  of 
  

   white 
  granular 
  quartz, 
  so 
  complely 
  shattered 
  or 
  broken 
  up 
  that 
  it 
  

   may 
  be 
  crumbled 
  with 
  the 
  hand, 
  and 
  requires 
  to 
  be 
  carefully 
  sup- 
  

   ported 
  by 
  timbers 
  as 
  the 
  excavations 
  progress. 
  Portions 
  of 
  it 
  are 
  

   in 
  a 
  sandy 
  or 
  powdered 
  state, 
  and 
  are 
  traversed 
  or 
  intermingled 
  

   with 
  harder 
  and 
  more 
  compact 
  masses, 
  and 
  with 
  a 
  greenish 
  por- 
  

   phyritic 
  rock, 
  like 
  that 
  of 
  the 
  central 
  mass 
  or 
  " 
  horse." 
  

  

  This 
  great 
  mass 
  of 
  friable 
  quartz 
  is 
  traversed 
  in 
  almost 
  every 
  

   direction 
  by 
  veins 
  or 
  streaks 
  of 
  the 
  richest 
  sulphurets 
  of 
  silver, 
  both 
  

   brittle 
  and 
  sectile, 
  and 
  with 
  free 
  gold 
  in 
  irregular 
  ragged 
  grains. 
  

   These 
  veins 
  or 
  masses 
  seldom 
  reach 
  a 
  thickness 
  of 
  more 
  than 
  two 
  or 
  

   three 
  inches, 
  and 
  are 
  often 
  merely 
  crusts, 
  or 
  coatings, 
  or 
  seams 
  in 
  

   the 
  quartz, 
  and 
  are 
  from 
  one-tenth 
  to 
  one-eighth 
  of 
  an 
  inch 
  thick. 
  

   It 
  is 
  more 
  common 
  to 
  find 
  the 
  silver 
  ore 
  ramified 
  irregularly 
  through 
  

   the 
  broken 
  quartz, 
  holding 
  it 
  together, 
  and 
  bearing 
  the 
  imprint 
  of 
  the 
  

   flat 
  surfaces 
  of 
  the 
  irregularly 
  crystalline 
  mass. 
  Galena 
  and 
  copper- 
  

   pyrites, 
  with 
  white 
  iron-pyrites, 
  are 
  associated 
  with 
  these 
  sulphurets. 
  

   In 
  some 
  of 
  these 
  irregular 
  veins, 
  and 
  in 
  cavities 
  connected 
  with 
  them, 
  

   beautiful 
  crystals 
  of 
  stephanite 
  (the 
  brittle 
  sulphuret 
  of 
  silver) 
  occur. 
  

   I 
  also 
  found 
  one 
  single 
  fragment 
  of 
  ruby 
  silver 
  with 
  the 
  stephanite, 
  

   but 
  it 
  is 
  very 
  rare. 
  Filaments 
  of 
  native 
  silver 
  are 
  frequently 
  found 
  ; 
  

   but 
  in 
  this 
  soft 
  ore 
  gold 
  is 
  the 
  most 
  generally 
  diffused 
  metal, 
  

  

  