The Poole Museum in the UK has a display behind glass of a rock donated to the museum by a young child.

I was part of a summer camp that was run in conjunction with the local university where we got to design a museum exhibit and put it on at the university's museum dedicated to anthropology and culture. We got to choose the theme of the exhibit (which didn't have to fit the museum) and chose the local fossils since they were easy to find in any creek and we all loved going out and hunting them. I remember my part of the exhibit was crinoids, and I wrote the title card and designed the display- the crinoids fossils were in some sand. I don't remember much else because we're talking almost 40 years ago. But I remember how awesome it was to be in the museum and see people looking at my display.

I learned how to paint minis in the basement of a hobby shop, basically as small town daycare while my mom worked on the floor above. My very first mini got put on display in that basement next to the work by the person who taught me. It was hilariously out of place. After college I was visiting again, like 10+ years later, it was still there proudly collecting dust. The guy who taught me had apparently recently died and they were going to put a bunch of the stuff in storage since the owner was having an emotionally difficult time seeing it all there. I managed to recover my mini just to be sure it didn't get lost with everything. Now I have it proudly displayed in my room. It's seen a lot of adventures