Constantan

Wrought from the poorly understood and esoteric energies leaking through the Planckian Nano-fissures associated with Manipulator misuse, Constantan is an exceptionally remarkable material. Constantan is a translucent, inky black substance that is simultaneously highly metallic and distinctly glassy in appearance.
Constantan behaves in a manner akin to that of an inductor in an electronic circuit, or a flywheel in a mechanical system. It strongly opposes physical changes applied upon it by its immediate surroundings. The measured temperature of a constantan sample always reads 0 K, absolute zero, however it a functionally perfect insulator with a thermal resistivity whose value is effectively infinite. No state change has ever been observed in a sample of constantan, as no change in temperature has ever been achieved.
Contantan is nigh indestructible. it utterly resists external forces that attempt to damage or deform it. Its bulk modulus, shear modulus, and Young's modulus all have values that are so unmeasurably high that they are effectively infinite. By extension its derived hardness is held to be infinite. This inability to deform constantan makes it impossible to work the lumps of the stuff into other shapes. It is feared by some material theorists that if a sample of constantan were to fracture under applied stress or strain, then the resultant release of energy would rival that of supernovae.
Constantan is electrically and magnetically inert. Like a superconductor it is a perfect diamagnet that rejects all magnetic fields, but unlike a superconductor it is a perfect electric insulator. Paradoxically, it is simultaneously completely opaque and transparent to light across the entire electromagnetic spectrum.
Constantan physically plugs up the Plankian fissures that it leaked out from, akin to a blood clot forming a scab on breached skin. As such, constantan's movement through space is reliant on the movement of the Plankian fissures which do not interact with gravity in a standard way. It can be difficult to force a piece of constantan to move in a desired fashion.