Chemically, yttrium is a metal that belongs with the rare earth series despite its position on the periodic table next to the transition metals. This relatively obscure metal has few applications because it is difficult to refine, making it expensive, and machining it makes it exponentially more so because the heat generated by tooling instantly oxidizes the metal. Special processes are needed therefore to avoid this.

Yttrium is very close to neutral gray but has a hint of yellow to it. It’s fairly stable in air, turning only a little darker over the course of several days in open air which is only noticeable against a freshly cut piece. It does, however, oxidize much more rapidly if allowed to come into contact with water.

The weight of each 10mm cube is 4.5±0.1g.