37Rb Rubidium

Year Discovered


Discovered By

Robert Bunsen and Gustav Kirchhoff of Germany

Biological Rating

Not necessary for life.


Named from the Latin word for deep red, rubidium is a very soft, silvery white metal. It is a fairly common metal, being 16th most abundant in the Earth’s crust. Like the other alkali metals, it is extremely reactive. If exposed to air, rubidium will burst into flame and if immersed in water, it will violently explode. Rubidium has a low melting point; it will melt and become liquid on very hot days. Rubidium has very few commercial or industrial uses. It is used in photocells, in special glass, and as a radioactive tracer. A common isotope of rubidium is radioactive, and because it is difficult to separate the isotopes, pure rubidium is slightly radioactive. Rubidium has future potential for use in very thin batteries, vapor turbines (where a vapor of rubidium ions replaces the normal armature of a generator), and in ion engines that could power spacecraft (like NASA’S Deep Space One).

Biological Benefits

Rubidium has no known biological use, although some scientists believe it could be a necessary trace element. Its possible function is unknown, although it is known to stimulate the metabolism.

Role in Life Processes

No known benefits to life processes, however it may have some medicinal benefits.

Percentage Amount in the Human Body: 0.001%


No rubidium-based minerals are known, but it occurs as an impurity in the minerals pollucite, leucite and zinnwaldite. It occurs as a substantial impurity in other alkali metal-based minerals.