Adamantium, the indestructible alloy that makes up Marvel character Wolverine's bones and claws, is a fictional metal. Created for use in the Marvel Comics universe, this substance was derived from a meteor and, in liquefied state, bonded to Wolverine's bones.
Though adamantium is fictional, the theory behind it has a basis in real science. Amorphous metals, also called glassy metals, have a non-crystalline disordered structure and are much harder than similar conventional metals. At Oak Ridge in 2004, a group of scientists produced just such a glassy steel in bulk. As for the bonding, a super-strong spider silk infused with aluminum at an atomic level was created in Germany. Just as with the fictional Wolverine's bones, the process involved bonding an organic substance with a metal.