I occasionally collect conversation pieces to have around the house. They make good ice-breakers if the kids have new friends over but they're also fun ways to explore science.
One of my first splurges was a Tungsten Cube, after seeing @Glaiel-Gamer talk about his. It turns out to have been a good investment; I paid $140 in 2018 and it now goes for $250. I don't think I would have paid $250 at the time but it has been a fun way to talk about mass and density, along with why Ant-Man packs so much force when he's tiny. It also surprises anyone you hand it to. I used my Amazon referral link for that one because why not.
Another fun one is the Flux Original, where you drop a ball through a magnetic tube and the ball slows down as it falls through. It's a fun thing to show people and it makes you think about magnets.
My latest oddity just arrived today and it's an interesting one: Ulexite, otherwise known as a "TV rock." The natural formation of ulexite behaves like fiber optics, so if you lay it down on something, the image of that thing appears on the surface of the stone, instead of looking through the stone at the image under it.
When I saw a video about this I thought, "I've been alive for 47 years and I've never heard of this. If it was actually impressive I'm sure I would have seen this by now." But I couldn't help myself, I bought a jumbo slab on Etsy.
The verdict: It really is a cool rock and it will make a nice conversation piece! It does feel weird to put it on things and see them appear on the surface. Did everyone already know about this but me, or are you surprised to learn about this too?