system
Given the following post, respond as if you're commenting on Reddit:
human
[Mythology] What are possible uses for a fragment of adamantine, a mythical metal that cannot be shaped or damaged by mortal means?
gpt
Assuming it's got a sharp point, you could use it to make a scribing tool that will mark anything.

Considering it's supernatural properties, and assuming magic exists too, then it might be able work as a kind of focus or battery for magical power.