Curious : Why US Mint issue silver medal to match the $100 High Relief rather than $1 nomination?

I tried to find old thread to read anything about this topic as well as searching the internet to learn the reasoning behind this to no avail. Please let me know. Thank you.
2015, 2016 and 2017 American Liberty consist of $100 High Relief / Ultra High Relief accompany by their matching silver medals.
Why would they not issue them in $1 nomination?
These just arrived to complete my gold coin.
3
Comments
2017


I believe they have legal authorization to mint gold coins, but not silver coins without Congressional authorization.
As above.
Silver (and copper, clad, etc.) requires Congressional authorization, but in the enabling legislation for gold and I think platinum, the Sec. of the Treasury was given some latitude on designs. (In the case of platinum, even the face value is up to the Sec. of the Treasury).
Gold can be classified as bullion and given whatever design is desired. The $100 denomination is nominal protection against counterfeiting - it permits prosecution, but does not really deter crooks.
@Paradisefound ...That is one super beautiful 2015W $100 gold coin.... Absolutely gorgeous....Cheers, RickO