CEMENT    RESOURCES    OF    WASHINGTON. 
383 
I  The  property  of  the  Keystone  Marble  Company  lies  near  the  locality  last,  described,  at  a 
koint  8J  miles  east  of  Bossburg,  a  station  on  the  Spokane  Falls  and  Northern  Railway. 
Hie  marble  outcrops  over  a  considerable  area  and  presents  ample  conveniences  for  quarry- 
tag.  The  stone  exhibits  great  diversity  in  color,  but  on  the  whole  approaches  a  pure 
•aleium  carbonate.  Interstratified  with  the  beds  of  marble  are  slates  and  quartzites. 
knalyses  of  two  varieties  of  marble,  made  by  Prof.  S.  Shedd,  of  Pullman,  are  as  follows: 
Analyses  of  white  and  gray  marble  from  quarry  s\  miles  east  of  Bossburg,  Wash. 
#  White 
marble. 
G  ray 
marble. 
-ilica      
0.98 
Trace. 
0  82 
Iron 
Alumina 
Lime 
53.96 
1.25 
43.  76 
54.81 
0  70 
43.  56 
In  the  vicinity  of  Ryan,  a  small  station  on  the  Spokane  Falls  and  Northern  Railway, 
there  are  many  outcrops  of  marble.  The  stone  makes  conspicuous  bluffs  on  both  sides  of 
Columbia  River  and  is  in  an  advantageous  position  for  economical  quarrying.  The  marble 
is  fine  grained,  is  mostly  of  a  light-gray  color,  and  is  unusually  hard.  An  analysis  of  the 
Ryan  marble,  made  by  Prof.  S.  Shedd,  of  Pullman,  is  as  follows: 
Analysis  of  marble  from  Ryan,  Wash. 
Silica 1.00 
Iron  and  alumina None. 
Lime 53. 96 
Magnesia 1. 60 
Carbon  dioxide 43. 27 
Independent  of  the  clay  represented  in  the  slates  noted  as  occurring  in  proximity  to  the 
limestones,  there  are  man}?-  places  in  Stevens  County  where  clays  exist  in  large  amounts. 
Some  of  the  clays  are  of  glacial  origin,  while  others  represent  residual  clays  derived  from 
granites.  As  a  type  of  the  latter  the  clays  in  the  vicinity  of  Clayton  may  be  mentioned. 
The  numerous  drill  holes  that  have  been  made  here  show  that  the  clay  beds  cover  several 
thousand  acres.  There  can  be  little  question  that  both  limestones  and  clays  may  be  had 
in  close  relationships  and  at  points  convenient  for  transportation,  so  that  in  time  Stevens 
County  may  become  an  important  producer  of  cement. 
