Über die Gewinnung hochwertiger Rubidiumpräparate aus Carnalliten

Analytical Reactions of Rubidium and Caesium

“…Sodium silieomolybdate {31, 32,38,45) is at present used to separate rubidium and caesium from potassium; it is, however, by no means quantitative for caesium, much less for rubidium, but serves for technical purposes.…”