I recently transferred about 2.3 kg of caesium from a round bottom flask into several smaller ampoules. We made it by reducing caesium chloride with lithium. At some point in the future I want to distill all the cesium into one large clean ampoule. But there’s still a lot of preparation needed for that project. Until then I thought some of you might enjoy these photos.

Clearing out an abandoned chemical warehouse, these are ingots of potassium we found.

Over the years, I have made many alkali metal ampoules, most of them containing cesium.

However, the other alkali metals are equally beautiful when they are in their pure form and free of any oxide layer. Rubidium is a great example, as you can see in these photos.

I prepared the rubidium by reducing rubidium chloride with lithium and distilled it twice under high vacuum directly into the ampoule. As the metal cools slowly, it forms these stunning dendritic crystal structures.

I did not weigh it, but I estimate that the ampoule contains approximately 70 grams of rubidium.

If you're interested in seeing a video about this process, you can find it here: https://youtu.be/yAET8uM_0QI