Dysprosium is likely the most valuable of the Rare Earth metals because it’s a key ingredient in the making of magnets. If magnets don’t immediately come to mind as a hot commodity, think again. Every machine with a moving part (and it’s not like there are many solid state machines) uses magnets. And the best magnets use a lot of dysprosium.

But there is another curious application for dysprosium. Alloy it with iron and terbium and you get a material with the strange property that its volumetric dimensions change in the presence of a magnetic field! A chunk of metal that changes shape when a magnet is around may sound like a plot device for a sci-fi movie but apparently there are quite a few applications for such a thing. And that’s probably one of the reasons for dysprosium’s growing demand.

Hey, what about a locking mechanism which works only with a key tuned to a precise magnetic strength?

Measures 15x8x1mm