|Cut cubes under oil.
This is a sample I prepared specifically for a film project, to make a 360-frame rotation image. It's scrap potassium from my anonymous sodium supplier, carefully cut up under oil to reveal shiny surfaces. When absolutely fresh, the surface is bright silver, but as you can see from the pictures this sample has turned slightly bluish. I could have worked harder to prevent this, but actually the blue cast is somewhat attractive in the photographs, and it is quite characteristic of the early stages of potassium oxidation. This helps to differentiate it visually from sodium, which would otherwise look identical. OK, I'm just rationalizing, I was too lazy and didn't have the right set up handy to create a really shiny sample, so I settled from this one. Still, it looks quite pretty, nicer I think than a silvery sample would.
I chose this sample to represent its element in my Photographic Periodic Table Poster. The sample photograph includes text exactly as it appears in the poster, which you are encouraged to buy a copy of.
Acquired: 12 May, 2005
Text Updated: 8 December, 2007