GRAPHITE  IN  THE  EASTERN  ADIRONDACK'S,  N.  Y. 
By  J.  F.  Kemp. 
General  remarks. — Graphite  is  now  attracting-  much  interest  in  the 
region  of  Lake  George  and  southern  Lake  Champlain,  New  York, 
and  as  important  observations  have  been  made  in  connection  with  the 
field  work  for  a  folio  now  in  preparation,  a  brief  sketch  of  the 
deposits  is  here  given. 
In  this  region  graphite  occurs  solely  in  Algonkian  strata.  The 
deposits  are  found  in  four  kinds  of  rock:  (1)  Pegmatite  veins,  (2) 
veinlets  of  graphite,  (3)  quartzites,  (4)  crystalline  limestones  with 
associated  gneissoid  strata.  All  four  have  been,  or  are,  the  objects  of 
serious  mining. 
1.  Pegmatite  veins. — In  the  pegmatites  the  graphite  is  coarsely  crys- 
talline and  in  its  outcrops  it  creates  the  impression  of  great  richness, 
but  it  is  difficult  to  find  enough  to  make  an  extended  opening  a  proba- 
ble source  of  profit.  Not  a  few  prospects  have  attracted  attention, 
but  the  pockety  and  uncertain  nature  of  the  deposits  has  made  all 
attempts  to  work  them  practical  failures  except  at  the  old  and  now 
abandoned  workings  on  Chilson  Hill,  Ticonderoga,  details  concerning 
which  will  be  given  below. 
The  pegmatites  contain  coarse  bunches  of  the  mineral  which  can  be 
cobbed  down  by  hand  and  do  not  demand  mechanical  concentration  to 
the  extent  needed  by  the  quartzites  or  limestones.  At  the  same  time 
when  one  compares  their  possible  yield  with  the  tonnage  demanded 
by  the  mills  working  on  the  quartzite,  it  is  at  once  realized  that  in  most 
cases  they  would  be  exhausted  in  a  very  short  time. 
In  the  pegmatites  the  graphite  is  more  especially  associated  with 
quartz,  but  it  is  also  involved  with  feldspar,  pyroxene,  hornblende, 
mica,  calcite,  scapolite,  apatite,  sphene,  and  other  less  common  min- 
erals. 
2.  Veinlets  of  graphite. — In  a  few  places,  as  at  Split  Rock,  near 
Essex,  on  Lake  Champlain,  narrow  veins  or  veinlets  of  graphite  have 
been  found  crossing  the  gneisses,  and  filling  fissures  up  to  an  inch  in 
width.  The  graphite  is  in  rather  coarse  leaves,  and  stands  at  an 
angle,  somewhat  less  than  a  right  angle,  to  the  wall  rock.  Considera- 
ble vein  quartz  is  mingled  with  it,  and  it  is  not  so  pure  as  one  would 
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