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Some people can pick a fight out of thin air, and some elements can, too. Rubidium is one such material, a highly reactive metal that wants so badly to find conflict with outside influences that it has little practical use outside of the laboratory. 

Akin to Other Alkali Metals

Like its friends in the Alkali category, rubidium ignites when exposed to water, and will oxidize very quickly when exposed to air. This means that, depending on the amount of humidity present, it may also ignite in the air alone. 

This element was first isolated in 1861 by two German chemists. They performed electrolysis on the mineral lepidolite in order to extract enough rubidium to study and found that it was even more reactive than potassium. 

Still, rubidium is quite abundant in the Earth’s crust, with an occurrence of about 90 parts per million. Because it is often found with cesium, and a number of other Alkali metals, extracting pure rubidium can prove rather tricky. 

Never The Star of The Show

Rubidium can be used in a number of applications, but it’s almost always less effective than one of the other Alkali metals. However, there are some laboratory uses for rubidium that are somewhat common, like in photocells and to get rid of oxygen in vacuum tubes. 


This element is also sometimes used to give fireworks their purple color, an application in which the volatile nature of rubidium isn’t a detriment. What’s more, since it is slightly radioactive and tends to accumulate in tumors, it can help medical professionals locate cancer. 

Rubidium may not be the most friendly element on the periodic table, but it’s here to stay, so humans may as well find as many ways as possible to make use of it.