It doesn’t have to be platinum. It could be made of lead.
It works because of the coinage power, not because of the metal.
No, you are wrong.
It does have to be platinum.
based on the authority granted by Section 31 U.S.C. § 5112 of the United States Code for the Treasury Department to “mint and issue platinum bullion coins” in any denominations the Secretary of the Treasury may choose.
I always ask for high denomination coins when the bank wants to know how i want my cash.
Most tellers were unaware that there are $100 coins
Actually it does have to be platinum. Congress authorized the US Mint to coin a certain number of gold coins of listed values, a certain number of silver coins of listed values and platinum coins. They intended platinum to be for collectibles also, but they didn't specify values and number.