This little-known element is ferociously reactive, very rare and has next to no marketable uses. Those three strikes make this little more than a scientific curiosity. And in the scientific world curiosities don't come cheap. Rubidium is consistently one of the priciest and most difficult to acquire pure elements.

It is actually only rare in the sense that it is concentrated in a few commercially valuable minerals. It comes in two isotopic 'flavors': the atom with 85 neutrons and another with 87. The lighter isotope is more common by a factor of two or three depending on source but the heavier, Rb87, is weakly radioactive. Like atomic-sized popcorn, those rubidium atoms are popping at a constant rate of 100,000 per gram per hour leaving behind newly formed strontium. This stream of new strontium is significant enough that it accounts for some 7% of the strontium metal present in the universe.

But really, that's little cause for concern. There are some 150 sextillion atoms of rubidium in one of these ampules. That's a 15 followed by twenty-two zeroes. We therefore unconditionally guarantee that for the remainder of your lifetime the sample sold will be contaminated by only a miniscule, truly trivial amount of strontium ;-)

Note additional options for this element on the Ampules section

CAS 7440-17-7