Right, I had fossils like that as a kid too, and even had a friend with a ranch in the East Bay that had an exposed fossilized seabed with lots of fossilized shells.
But typically those are extracted from deposits with lots of similar pieces, like the three-foot-long slab of fossilized seabed I had. Professionals might carefully carve something like that up and turn it into lots of small fossils of fish, but they all came from the same chunk of rock.
That's what I meant by "large communities of small things".
So, it's possible that some bunker of physical storage of wealth, with gold bars for instance, will survive a hundred thousand years longer than most of the rest of our civilization. Or, maybe one of our many many landfill deposits will end up with just the right conditions to preserve for a long time the preservable stuff. But I don't think bits of gold jewelry will just be sifted out of the dirt.
Come to think of it, the best bet for evidence of our civilization a million years from now are currently the bits we've left behind on the moon, and Musk's roadster! (The latest calculations have a 6% chance of it crashing back to Earth within the next 3.5 million years -- but it will continue to swing back around every hundred years or so until then.)