iridium

"...the team suggests that frequently quoted iridium values are incorrect.

Woz is, for me, the ISO standard geek, the distillation of all that I aspire to. Somewhere in Paris is a vault, and in that vault is a platinum-iridium Steve Wozniak, against which all of us are judged and found wanting.

This is the first time anyone has used non-precious metal catalysts to split water at a voltage that low. It's quite remarkable, because normally you need expensive metals, like platinum or iridium, to achieve that voltage.

I think the part about the kilogram is missing the point -- it's not that a pure silicon crystal sphere is a better artifact to be the kilogram than the platinum-iridium cylinder.

Using a comparison with another extraterrestrial element deposited in the impact - osmium - they were able to deduce that the collision deposited less debris than has previously been supposed...The recalculated iridium value suggests a smaller body hit the Earth.