﻿60 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  For 
  the 
  various 
  grades 
  of 
  glass, 
  sands 
  of 
  varying 
  purity 
  may 
  be 
  

   used. 
  For 
  the 
  highest 
  grade 
  such 
  as 
  is 
  used 
  in 
  cut 
  glass 
  ware 
  and 
  

   in 
  lens-making 
  a 
  pure 
  white 
  sand 
  containing 
  practically 
  lOO 
  per 
  

   cent 
  quartz 
  or 
  silica 
  must 
  be 
  used, 
  as 
  a 
  fraction 
  of 
  a 
  per 
  cent 
  of 
  

   iron 
  will 
  impart 
  a 
  greenish 
  tinge 
  to 
  the 
  glass, 
  the 
  presence 
  of 
  clay 
  

   will 
  detract 
  from 
  its 
  brilliancy 
  and 
  transparency, 
  while 
  other 
  im- 
  

   purities 
  will 
  also 
  ruin 
  its 
  value. 
  For 
  the 
  manufacture 
  of 
  window 
  

   glass 
  and 
  plate 
  glass, 
  where 
  a 
  slight 
  greenish 
  tinge 
  will 
  do 
  no 
  harm, 
  

   a 
  sand 
  containing 
  as 
  much 
  as 
  one 
  half 
  per 
  cent 
  of 
  iron 
  oxid 
  is 
  

   frequently 
  safely 
  used, 
  while 
  sands 
  with 
  a 
  slightly 
  greater 
  per- 
  

   centage 
  of 
  iron, 
  have 
  been 
  used, 
  the 
  color 
  being 
  removed 
  during 
  the 
  

   fusion 
  by 
  certain 
  oxidizing 
  agents 
  such 
  as 
  manganese 
  or 
  arsenic 
  

   which 
  oxidizes 
  the 
  green 
  ferrous 
  silicate 
  to 
  a 
  less 
  conspicuous 
  ferric 
  

   silicate. 
  For 
  the 
  cheaper 
  grades 
  of 
  glass 
  such 
  as 
  are 
  used 
  in 
  bottle 
  

   manufacture, 
  structural 
  glass, 
  etc., 
  a 
  sand 
  of 
  less 
  purity 
  may 
  be 
  

   used 
  but 
  rarely 
  does 
  the 
  percentage 
  of 
  silica 
  fall 
  below 
  97.5. 
  

  

  Aside 
  from 
  the 
  consideration 
  of 
  the 
  size 
  of 
  the 
  deposit, 
  the 
  dis- 
  

   tance 
  from 
  railroads 
  or 
  waterways, 
  cost 
  of 
  haulage 
  etc., 
  the 
  owner 
  

   of 
  a 
  prospective 
  glass 
  sand 
  deposit 
  should 
  make 
  a 
  thorough 
  exami- 
  

   nation 
  of 
  his 
  sand 
  under 
  a 
  microscope 
  to 
  determine 
  its 
  probable 
  

   purity 
  and 
  physical 
  characteristics. 
  The 
  necessary 
  qualifications 
  

   to 
  be 
  observed 
  by 
  simple 
  tests 
  are 
  summed 
  up 
  by 
  Burchard^ 
  as' 
  

   follows 
  : 
  

  

  The 
  sand 
  should 
  be 
  nearly 
  white 
  in 
  color 
  ; 
  it 
  shouM 
  be 
  of 
  

   medium 
  fineness 
  (passing 
  a 
  20 
  to 
  50 
  mesh 
  horizontal 
  sieve) 
  ; 
  the 
  

   grains 
  should 
  be 
  uniform 
  in 
  size, 
  even 
  and 
  angular, 
  or, 
  less 
  prefer- 
  

   ably, 
  they 
  may 
  be 
  rounded. 
  A 
  simple 
  chemical 
  test 
  may 
  be 
  em- 
  

   ployed 
  by 
  heating 
  the 
  sand 
  in 
  a 
  dilute 
  acid. 
  Effervescence 
  indi- 
  

   cates 
  the 
  presence 
  of 
  lime 
  ; 
  loss 
  of 
  color 
  shows 
  the 
  presence 
  of 
  

   clay 
  impurities. 
  Iron 
  in 
  the 
  most 
  minute 
  quantities 
  may 
  be 
  de- 
  

   tected 
  by 
  dissolving 
  sand 
  in 
  hydrofluoric 
  acid 
  and 
  adding 
  potas- 
  

   sium 
  ferrocyanid 
  which 
  produces 
  a 
  blue 
  precipitate 
  if 
  iron 
  is 
  pres- 
  

   ent. 
  Complete 
  quantitive 
  analysis 
  as 
  well 
  as 
  a 
  furnace 
  test 
  should 
  

   be 
  made 
  as 
  a 
  final 
  determination 
  of 
  the 
  character 
  of 
  a 
  prospective 
  

   sand. 
  

  

  Some 
  sands 
  may 
  be 
  partially 
  purified 
  by 
  washing 
  processes 
  which 
  

   remove 
  clay, 
  mica 
  scales, 
  organic 
  matter, 
  etc. 
  while 
  in 
  some 
  cases 
  

   where 
  the 
  iron 
  exists 
  as 
  magnetite 
  grains 
  some 
  form 
  of 
  magnetic 
  

   separation 
  may 
  be 
  effective. 
  

  

  The 
  glass 
  sand 
  industry 
  has 
  been 
  on 
  the 
  decline 
  in 
  this 
  State 
  

   for 
  several 
  years 
  and 
  at 
  present 
  the 
  only 
  producing 
  area 
  is 
  that 
  

  

  1 
  U. 
  S. 
  Geol. 
  Stir. 
  Bui. 
  285. 
  p. 
  454. 
  

  

  