Looks like something you give to a pokemon to evolve quicker
Notice that this isn't posted from r/MineralPorn?
It's because the karmawhoring OP knows it would get called out as fake and downvoted.
I'm pretty sure that I was digging for that in mines in Webkinz a few years ago.
Why do these keep showing up? Its cool, but it is a manmade process.
I actually thought it was a rainbow scale from the game Ty the Tasmanian tiger for a second. I don't know why....
I take it to Melchoir and trade it in for Rainbow. Only this weapon will be able to defeat Lavos.