Tungsten is an extremely rare element with just 100 parts per billion contained within the Earth’s crust. It has the highest melting point of any metal at 3,410° C (6,170° F) and as such, it is an incredibly difficult metal to process and work with.
However its ability to withstand high levels of compression and heat have made it an ideal alloy for rocket engine nozzles, radiation shielding and aerospace tooling.