[What the hell. She squints.]

Yeah, an artifact is just a thing made by people. So technically you could bring anything you find that was made by people. A plate? A basket?

[No idea. As for shells, well.]

I can help you look for good shells if you want. Probably if you grab some that aren't broken, it'll be good enough. If they needed something specific they would've given you more details, right?

[Or this is all an elaborate trap, but that seems kind of unlikely.]