GOLD-BEARING    RIVER    SANDS    OF    N.  E.   WASHINGTON.  61 
five  times  the  ordinary  amount  was  taken  for  fusion  and  quantitative 
determinations  were  made  where,  by  ordinary  methods,  nothing  but 
traces  could  have  been  reported.  The  colors  of  gold  were  found  to 
range  in  value  from  less  than  0.0005  to  0.02  cent,  the  average  being 
about  0.002  cent.  Nearly  all  of  this  is  flour  rather  than  flake  gold 
and  although  very  fine  it  is  usually  not  difficult  to  save  in  panning. 
Some  of  the  colors  which  appear  to  be  larger,  however,  are  thin 
flakes  and  scales  that  are  very  hard  to  separate  from  the  black  sand. 
There  is  a  noticeable  difference  in  the  size  of  the  colors  at  various 
points  along  the  river,  some  of  the  bars  being  characterized  by  very 
fine  gold,  and  that  of  others  being  comparatively  coarse.  Generally 
the  colors  of  any  particular  bar  or  pay  streak  are  nearly  uniform  in 
size  and  appearance,  but  there  are  a  few  notable  exceptions  to  this 
rule,  some  of  the  localities  affording  coarse  flakes  as  well  as  uniformly 
fine  flour  gold,  seeming  to  indicate  a  local  source  of  supply  for  part  of 
the  gold. 
ASSOCIATED   MINERALS. 
The  gold  is  associated  with  black  sand  containing  a  large  amount  of 
magnetite  and  somewhat  smaller  amounts  of  ilmenite,  zircon,  garnet, 
and  other  heavy  minerals.  Platinum  probably  also  occurs  in  small 
quantities,  though  its  presence  was  not  detected  in  the  field. 
An  average  sample  of  sand  was  run  over  the  Wetherill  separator  at 
the  concentrating  pavilion  and  its  mineral  constituents  were  deter- 
mined as  follows: 
Mineralogical  composition  of  average  sand  from  Columbia  River  terraces. 
Magnetite 0.3 
Ilmenite 1 
Garnet 1 
Zireon ." 1 
Quartz 39.  4 
Others 60 
100 
One  large  color  of  gold  and  10  to  20  small  colors  of  platinum. 
The  amount  of  black  sand  in  the  pay  streaks  is  much  greater  than 
in  this  sample,  in  some  places  reaching  3  or  4  per  cent. 
TYPICAL  LOCALITIES. 
Although  there  is  probably  some  gold  in  the  sands  of  the  river 
throughout  its  length,  the  gold-bearing  terraces  on  either  side,  which 
are  called  bars,  are  not  continuous.  Those  adjacent  to  the  right 
bank  that  were  examined  are  Nespelem  Bar,  at  the  mouth  of  Nes- 
pelem  River;  Hell  Gate  Bar,  a  few  miles  above  the  Sanpoil;  Peach 
Bar,  opposite  Peach  post-office;  Sixmile  and  Ninemile  bars,  6  and  9 
miles    respectively   above    Spokane    River;    Wilmot    Bar,    opposite 
