398  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1906,  PART    I. 
The  grinding  mill  of  Kinkle' s  Sons  is  located  at  the  quarries  and  is 
similar  in  equipment  to  most  feldspar  mills  elsewhere,a  except  that? 
the  spar  as  it  comes  from  the  chasers  goes  to  a  vibration  separator, 
only  the  tailings  being  sent  to  the  ball  mills.  For  pottery  spar  this 
separator  is  provided  with  a  140-mesh  screen,  but  in  the  preparation 
of  spar  for  glass  manufacture  only  a  60-mesh  screen  is  required. 
In  one  sample  of  the  "No.  3"  spar  measured  under  the  microscope 
no  particles  over  0.01  inch  (0.25  mm.)  in  diameter  were  seen.  Most 
of  the  material  was  under  0.002  inch  in  diameter  and  the  finest  par- 
ticles were  under  0.0001  inch. 
The  ground  spar  is  usually  shipped  in  bags.  All  of  the  material 
Iron!  this  quarry  and  mill  is  hauled  by  team  5  miles  to  Bedford  sta-; 
tion,  on  the  New  York  Central  Railroad.  The  average  price  for  the 
crude  "No.  1"  spar  is  about  $5,  for  the  ground  "No.  3"  spar 
about  $6.50,  and  for  crude  quartz  about  $3  per  ton,  f.  o.  b.  cars 
at  Bedford  station.  The  "No.  1  "  and  "No.  2"  grades  for  pottery 
use  are  shipped  mainly  to  Trenton,  X.  J.,  and  East  Liverpool,  Ohio, 
though  small  amounts  have  been  shipped  as  far  as  Portland,  Oreg. 
HOBBY   QUARRIES. 
A  small  quarry  owned  by  Albert  Hobby,  of  Bedford,  N.  Y.,  and 
operated  by  Max  Buresch,  has  recently  been  opened  in  the  town  of 
North  Castle,  near  the  west  side  of  Mianus  River,  about  1J  miles 
southeast  of  the  Kinkle  quarry.  The  quarry  is  situated  on  a  steep; 
eastern  hill  slope  and  is  about  100  feet  wide,  150  feet  long,  and  40  feet 
in  maximum  depth.  No  exposures  of  the  surrounding  rocks  were] 
observed  near  the  quarry.  The  pegmatite  shows  masses  of  pure 
feldspar  8  to  10  feet  across  associated  with  masses  of  pure  quartz, 
sonic  of  which  are  15  feet  across.  The  quartz  is  in  part  white  and  in 
part  a  beautiful  rose  tint.  There  is  almost  no  intergrowth  of  quartz 
and  feldspar.  The  feldspar  is  buff  colored  and  is  shown  by  micro- 
scopic examination  t<>  he  microcline  (pot  ash  feldspar,  probably  contain- 
ing a  litlle  soda).  Its  analysis  is  No.  3  of  the  table.  Small  and  very 
thin  plates  of  muscovite  occur  along  some  of  the  cleavage  planes  in 
the  feldspar,  hut  they  are  not  abundant  enough  to  affect  the  quality 
of  the  spar  materially.  Muscovite  in  larger  plates  is  mainly  segre- 
gated in  somewhat  irregular  bands  in  association  with  black  tour- 
maline in  prismatic  crystals  that  reach  1  \  inches  in  diameter. 
This  quarry  differs  from  the  Kinkle  quarry  in  the  fact  that  the 
feldspar  is  practically  all  buff-colored  microcline,  and  in  the  more 
complete  separation  of  quartz  and  feldspar,  graphic  granite  being 
apparently  wholly  absent.  The  present  exposures  cover  only  a 
small  area,  and  it  is  impossible  to  predict  the  extent  or  uniformity  of : 
a  .For  description  of  grinding  process  see  p.  387  of  this  bulletin. 
