Game of Thrones may be a fictional universe, but materials chemist Ryan Consell decided to take a stab at what it would take to mimic Valyrian steel in the real world. He writes:
One possible candidate is that Valyrian steel is a metal matrix composite, or MMC. These employ a metallic framework, which provides some toughness and tensile strength to the material, and have a much harder material, like a ceramic, embedded into them which could provide that indelible edge.
It sounds plausible, but the lack of Dragonfire and magic are going to make this one a little tough to replicate.
See the video after the break.