Vin's mother's earring

Vin's mother's earring begins as a seemingly innocuous piece of jewelry but gradually reveals itself as a critical Hemalurgic spike that fundamentally shapes the fate of Scadrial. Originally belonging to Vin's mother, the earring carries the power of Ruin's influence and serves as a conduit for divine manipulation throughout the series. Its true nature is only fully understood in the final book, where it becomes central to the climactic confrontation between Preservation and Ruin, ultimately determining the outcome of the world's salvation.