64 W. Lindgren — Monazite from Idaho. 



grains of a dark yellowish brown mineral with waxy lustre, 

 sometimes showing crystallographic faces. It was found 

 impossible to extract but a small part of the iron ore by the 

 magnet; there was practically no magnetite present. This 

 sand was examined by Dr. Hillebrand qualitatively with the 

 result of finding phosphoric acid, cerium metals and thorium. 

 The yellowish brown mineral is therefore in all probability 

 monazite. 



Although the monazite occurs in considerable quantity, it is 

 doubtful whether the mineral can be profitably extracted 

 except possibly as a by-product obtained from the gold wash- 

 ings. 



Washington, D. C, May, 1897. 







