Rubidium carbonate

Rubidium carbonate, Rb2CO3, is a convenient compound of rubidium; it is stable, not particularly reactive, and readily soluble in water (2.25 grams per millilitre), and so appears to be the form in which rubidium is usually sold.

It can be prepared by adding ammonium carbonate to rubidium hydroxide. 

It is used in some kinds of glass-making, and as a part of a catalyst for preparing short-chain alcohols from feed gas.

Rubidium carbonate as a dietary supplement is supposed, according to 'high pH therapy', to have beneficial effect on certain cancers.