It seems to me that the clear intent of the US Constitution is that the US Congress, particularly the House, initiates entirely new monetary resources.
No matter how you cut it, a trillion dollar coin is new resources.
Also, any effort to assign the value of a trillion dollars to a coin flies is fraud. The market price of platinum is available for all to see, the historic price is available, and the futures price is available.
For anyone to claim they have a trillion dollars worth of platinum would require that they have more than a single coin or that the single coin be the size of a mountain.
Otherwise, they are perpetrating fraud.
And we SURELY don't want that!
Notice that US gold coins - real 1oz ones - have a face value of $20 yet cost some ~$1500 to buy.
This has led to some rather interesting economic/tax consequences.
Silly plebian! Don’t you know that Chairman Obama is above the law?
Not at all.
Congress has the power (and the duty) to "coin money, and regulate the value thereof".
Congress set the price of gold from 1792-1971 and set the price of silver from 1795-1964, and there was nothing fraudulent about THAT.
Congress has the power to mint platinum coins and set the value at USD one trillion/ounce. In fact, they have the power to pay off the national debt that way.
Since I presume they would not allow free coinage (i.e., they wouldn't pay YOU UDS one trillion/oz), it might be a hard sell to our foreign friends, but the notes we use to pay them now are essentially without value other than that decreed by Congress.
The "money question" is rising from the grave. Can YOU define "money"? Can you define "dollar"?
This could work.