Ranking minerals by "most rare" is stupid. They simply don't have enough data.
> you might mistaken it for amber or topaz
I suspect that there are dozens of other extremely rare minerals out there that have not yet been found or mistaken for different ones. Correctly estimating their relative abundance is impossible and pointless as the rarest will be single cases. In fact, the rarest mineral ever has likely not been discovered yet. I bet there is some famous math/statistics problem about this kind of situation.
And I wonder if any rare minerals have been classified by governments (or individuals) for whatever reasons. (Probably yes)
As with most pronouncements like this, you just have to mentally append "(known so far)" to the end and it will make sense. That's the implicit context for almost all of them. We can only say what we know, so far. For the reasons you stated, I don't think anyone actually thinks they know the absolute rarest mineral on earth.
> you might mistaken it for amber or topaz
I suspect that there are dozens of other extremely rare minerals out there that have not yet been found or mistaken for different ones. Correctly estimating their relative abundance is impossible and pointless as the rarest will be single cases. In fact, the rarest mineral ever has likely not been discovered yet. I bet there is some famous math/statistics problem about this kind of situation.
And I wonder if any rare minerals have been classified by governments (or individuals) for whatever reasons. (Probably yes)