392  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1906,  PART    I. 
schists.  As  at  the  other  feldspar  localities  much  of  the  commercial 
material  quarried  is  a  coarse  graphic  intergrowth  of  quartz  and  feld- 
spar, though  there  are  also  very  considerable  amounts  of  pure  feld- 
spar. The  latter  is  mostly  cream  colored,  with  here  and  there  bluish- 
gray  streaks  and  blotches.  It  is  a  potash  feldspar,  though  small 
amounts  of  soda  and  lime-soda  feldspar  are  associated  with  it.  Both 
black  mica  and  black  tourmaline  are  present,  but  they  are  abundant 
only  in  places  and  are  readily  separable  from  the  commercial  spar.  A 
considerable  amount  of  quartz,  white  to  dark  gray  in  color,  occurs 
and  is  saved,  though  at  present  finding  no  market.  At  the  time  of  the 
writer's  visit  (August,  1906)  about  300  tons  of  quartz  were  piled  up 
at  the  quarries.  There  seem  to  be  large  amounts  of  excellent  spar 
available  at  Mount  Apatite  for  some  time  to  come. 
A  smaller  quarry,  operated  by  A.  R.  Berry,  is  situated  in  the  town 
of  Poland,  about  1  mile  south  of  Mount  Apatite.  Irregular  excava- 
tions here  cover  an  area  of  about  2  acres  and  have  a  maximum  depth 
of  18  to  20  feet.  The  spar  is  all  sold  to  the  Maine  Feldspar  Company 
and  hauled  about  3  miles  to  their  mill  at  Littlefield.  The  character 
and  mode  of  occurrence  of  the  feldspar  and  quartz  are  similar  to  those 
at  Mount  Apatite.  At  both  these  localities  lithium  mica  is  occasion- 
ally found  and  tourmalines  and  beryls  of  fine  gem  quality  also  occur. 
They  are  not  abundant  enough,  however,  to  pay  for  working  these 
deposits  for  gems  alone. 
HEBRON,  OXFORD  COUNTY. 
A  small  feldspar  and  mica  mine  has  been  opened  during  the  last 
year  (1906)  about  A\  miles  north  of  Hebron  village,  near  the  Buck- 
field  road.  This  mine  is  located  on  the  farm  of  Alton  Ilibbs  and  is 
being  operated  by  J.  A.  Gerry,  of  Mechanic  Falls,  Me.  The  pegmatite 
is  exposed  for  a  distance  of  :>()()  to  350  feet  along  the  southwest  side  of 
a  small  creek  valley,  the  average  width  of  outcrop  being  about  30  feet. 
Schists  bound  the  pegmatite  mass  on  its  southwest  side,  their  trend 
varying  from  N.  30°  W.  to  N.  50°  W.  and  averaging  about  N.  45°  W.. 
Their  average  dip  is  45°  NE.  The  northeast  border  of  the  mass  is 
wholly  obscured  by  glacinl  drift,  which  fdls  the  bottom  of  the  valley. 
The  strippings  and  small  excavations  already  made  show  numerous 
bodies  of  pure  feldspar  2  to  3  feet  across  and  much  graphic  granite  con- 
taining only  a  small  percentage  of  quartz.  It  is  estimated  that  60 
per  cent  of  the  material  mined  is  of  commercial  grade.  No  predic- 
tions can  be  made  as  to  the  continuance  of  this  rock  beyond  the  lim- 
ited area  of  present  exposure  or  in  depth.  It  is  probable,  however, 
that  its  greatest  extent  is  in  a  northwest-southeast  direction,  parallel 
to  the  trend  of  the  neighboring  schists.  The  feldspar  is  of  the  potash 
variety  and  is  cream-gray  to  blue-gray  in  color.     Black  mica  is  scanty 
