Trowsa said:
Is this spotting a common problem with only the SML? Or something that silver coins of all types are prone to?
It can & does happen with any silver, really.. Nothing is immune.
Proof coins can get them, too.
I have a few minted bars that developed some milk-spots. Even a cast bar!
FYI, that photo of the 2009 Maple is an extreme example.
In my experience, anyway, if it does happen, it will only be a few smaller spots.
There are some mints & years that can be more prone to them..
Maples, Philharmonics & Somalia Elephants immediately jump to mind. But that doesn't stop me from buying a few of those each year.
Environmental conditions might play a role, like constant high humidity where they're stored.
But again, any modern piece can get them -- and oftentimes it's not a huge deal. I can live with a few spots here & there.
It can be unfortunate.. But for a lower-premium raw bullion coin, it's not the end of the world. Well, maybe for most people.
Official mints across the globe are aware of the issue. Apparently at least one is working on a solution.
They should all follow suit..