Mithril, known scientifically as silversteel or, in aerospace circles, superaluminium, is a supermetal produced from refined mithrilite ore. Its most remarkable property is the combination of structural qualities it should not be able to simultaneously possess: a density near-identical to that of pure aluminium (approximately 2.7 g/cm³), paired with tensile strength, resistance to deformation and penetration, and elasticity more consistent with high-grade steel alloys. By all known metallurgical models, this combination is physically impossible. Mithril does not behave this way because the models are incomplete.
The military and aerospace applications are immediately obvious. An aircraft airframe constructed from mithril carries conventional steel-level structural protection at a fraction of the weight penalty, dramatically improving performance while providing meaningful resistance to small-arms fire and shrapnel. Mithril infantry armour offers comparable protection to steel plate at a weight that does not substantially impede the wearer. In the mid-1960s, where weight is one of the primary constraints on both aviation design and a soldier's loadout, mithril represents a generational advantage for any force that can field it in quantity.
The limitation is supply. Mithrilite deposits are rare even by algeochemical standards, and the refining process is technically demanding. Oceanykan mithril production is currently sufficient to supply specialist military units and high-priority aircraft programmes, but not to equip line infantry or produce vehicles in bulk. Federal export controls are strict; mithril samples have reached foreign intelligence services, but industrial production outside Oceanyka remains impossible without the ore.