Item from Mistborn by Brandon Sanderson
Preservation's god metal. Anyone who burns a bead of lerasium becomes a full Mistborn, regardless of bloodline. Only a handful of beads have ever existed, making it the rarest substance on Scadrial.
Lerasium is Preservation's body condensed into metal, the counterpart to atium. Its most dramatic property is that anyone — Allomancer or not — who ingests and burns a bead becomes a full Mistborn with access to all Allomantic metals. The original Mistborn were created this way: Rashek left beads of lerasium at the Well of Ascension, and those who consumed them became the progenitors of all noble Allomantic bloodlines. Every Allomancer in the Final Empire descends from those original lerasium Mistborn, their powers diluted over generations into individual Mistings. The metal's extreme rarity means that by the events of the series, lerasium is essentially mythical.
Small, lustrous beads of pale gold metal with an almost luminous quality. They seem to glow faintly from within, warm to the touch. The metal has a weight and presence that feels significant — even non-Allomancers sense something extraordinary about it.