The kilogram has been redefined in a way that does not refer to the International Prototype Kilogram. That kind of makes the International Prototype Kilogram useless.

So what will happen to it? Can I have it?

  • $\begingroup$ I'm voting to close this question as off-topic. $\endgroup$ – Qmechanic Nov 17 '18 at 3:59
  • 1
    $\begingroup$ +1. Please do not close this Q. It's part of history that is happening right now. It's as valid a question as any about unit redefinitions in the past, and these weren't frowned upon. $\endgroup$ – kkm Nov 18 '18 at 22:22

Can I have it ?

The 1 Kg block of metal is 90% Platinum and 10% Iridium.

At today's prices on the commodity market that will cost you about USD $ 29,237. You can try emailing the owners, but I suspect they'll pop that sucker in a museum (or hang onto it as an investment). The actual value at auction would probably be considerably higher given it's history (and that's probably ten or a hundred fold, not just a few dollars more :-) ).

In fact it's essentially in a museum now, as it is kept in strictly controlled conditions and no one touches it (to avoid altering it, quite apart from it's monetary value).

That kind of makes the International Prototype Kilogram useless

Not necessarily. It's still a reference mass and may have legal value in keeping in the event that some (odd) legal dispute pops up where someone makes an issue about the historical value of the kilo.

There is a need to keep things like this simply so you have a complete record of the standard.


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