[hinckley buzzard]

Somewhere in the South Sea Islands they used large stone wheels as money--they just stayed in one spot and it was understood who the owner was. They were too big to steal, and it worked fine. Why should we waste a bunch of platinum when a good big chunk of carved sandstone will serve just as well.

[KarlInOhio]

Why should we waste a bunch of platinum when a good big chunk of carved sandstone will serve just as well.

Because that would require a law. It is already legal to make platinum, legal tender coins, primarily for the mint to make collector's items, but unlike gold and silver Congress never put a limit on the value of the platinum coins allowed so a trillion dollar coin could get through that loophole. Big rocks aren't on the list.

And it wouldn't even be a "big chunk" of platinum - just something large enough to hold a one followed by a dozen zeroes. One ounce per coin should be more than enough.