i6o 
A  Piece  of  Pitchblende. 
\       April,  1909. 
(  Am.  Jour.  Pharm. 
Here  is  a  typical  specimen  of  pitchblende,  and  we  will  have  a 
better  view  of  it  by  throwing  its  image  upon  the  screen.  You  notice 
that  its  features  are  not  prepossessing;  there  is  no  indication  of 
crystal  form,  and  the  complexion  is  dusky  with  a  resin-like  lustre. 
In  this  respect  the  mineral  resembles  blende,  and  for  this  reason  was 
formerly  mistaken  for  an  ore  of  zinc. 
Old  Werner,  the  father  of  mineralogy,  believed  it  to  be  an  iron 
ore,  while  others,  on  account  of  its  high  specific  gravity,  suspected 
that  it  contained  tungsten. 
Our  specimen  comes  from  Joachimsthal,  a  place  in  Bohemia 
which  has  long  been  famous  for  its  silver  mines,  and  from  which  the 
German  thaler  and  our  dollar  derive  the  names.  It  is  the  only 
locality  where  pitchblende  is  actually  mined,  and  the  Imperial  factory 
at  Joachimsthal  is,  I  believe,  the  only  plant  where  the  mineral  is 
worked  up  on  a  large  scale. 
But  pitchblende,  or  uraninite  as  mineralogists  prefer  to  call  it,  is 
found  also  in  many  other  localities,  both  in  Europe  and  America. 
In  some  cases  it  forms  an  original  constituent  of  granite  rocks,  while 
in  others  it  occurs  in  deposits  of  metallic  ores.  Considerable  quanti- 
ties of  the  mineral  are  met  with  in  certain  parts  of  Saxony  and 
Bohemia,  at  St.  Stephens  in  Cornwall,  in  Mitchell  County,  North- 
Carolina,  and  in  Colorado  and  South  Dakota.  Two  of  the  most 
interesting  varieties,  cleveite  and  brbggerite,  come  from  Norway. 
Pitchblende  from  Joachimsthal 
