As a guy who has never faked paperwork on his minerals, I can assure you there’s definitely workarounds. And a lot of them aren’t even illegal.
There’s lots of stones & nuggets found each year in regions known to be rich in minerals. Some companies and even governments run sites open to the public where they can pan or search.
www.emeraldhollowmine.com
gemmountainmt.com
Sometimes people simply find stuff.
A woman determined to find a diamond for her engagement ring found one on the last day of her trip. (Source: Arkansas' Crater of Diamonds State Park)
www.fox10tv.com
You can keep gold nuggets found on public land if you were “casually prospecting”- not using commercial mining equipment- but you will be taxed.
(Rules may vary in other countries, obviously.)
Still worried? Buy up the contents of a storage locker. Say it was in there. (Superman wouldn’t do this, but I’m not him.)
IOW, “I found it.” clears
a lot of barriers.
Beyond that? Again, I’ve been buying & selling gems & precious metals- as a hobbyist- for decades, and I can tell you In-person queries will often get different results than calling around.