Shigawire, the prototype of mono-molecular wire, first making its appearance in Dune (1965), is a metallic extrusion produced naturally from a ground vine, and is notable for its incredible tensile and mechanical strength. Shigawire is able to cut through almost any material cleanly. It finds widespread use as a weapon system, but more importantly as an information recording material. Shigawire is able to accept magnetic fields imprinted along its length in the style of magnetic tape, giving rise to the wire projector, which displays holographic images and films whose data is imprinted on a shigawire reel. Minimic film is mono-molecular shigawire which has been used to record data - great care is needed while handling this material.
My first thought was Mithril from LOTR made by the elves.