Rhenium is the last stable element to be discovered, found in 1925, before all of the nuke-y ones. It’s extremely rare, and one of the densest of elements. It’s used in alloy form, primarily in high-tech purposes like combustion chambers, turbine blades, and exhaust nozzles of jet engines.
Two pale silvery darts were tucked like bullets in a bandolier, into the thick cording of the jacket’s frogged front, their blood-red, paper-thin plastic flights pointing toward Number Four’s ceiling.
She rolled a third between thumb and forefinger, as if she might decide to smoke it. “Tungsten,” she said, “and rhenium. Alloyed, they’re superheavy.” She sighted along the dart’s black tip, almost invisible in this light.
It may seem like a frivolous use of such a heavy-duty material, but darts are serious business for a lot of people. Competitive dart players, for one, but also Hollis Henry’s sidekick in Zero History, Heidi, who fetishizes her super-dense darts, and eventually uses one to subdue a henchman with one to the face.
For the average user, darts range in materials, starting with wood at the simplest, to brass at the most basic, to a nickel/silver alloy at the most common competitive level. But for the professional, the tungsten alloy dart is the way to go. Tungsten, also known by its archaic name Wolfram, is a truly unique compound, known for having the highest melting point of all the elements (3422 °C, 6192 °F), and being super-dense, at 19.3 times the density of water.
So for a dart, it’s a perfect material, with a high weight per volume that makes for a ferocious, tiny missile. While a brass, or a nickel/silver dart can be plenty dense and cheap, it’s also softer than a tungsten alloy dart, so it’ll wear down faster. A tungsten alloy dart—typically mixed with anywhere from 5-20% nickel—will also have a sharper point, which for competitive purposes makes for a better set of bull’s-eyes.
So where does the rhenium come in?
Rhenium is one of a small number of elements that is denser than Tungsten, just shy of platinum. So the highest-end, arguably absurd compound for a dart, would be a tungsten-rhenium alloy.
They are sleek, heavy, sharp and pricey. Hard to find, and the best dart money can buy. Perfect to jab into the skull of a camo-wearing ne’er-do-well.