Synchrium

Physicists have speculated that further up the periodic table there may be "islands" of possible elements that are stable despite having super large nuclei.
In our universe only one of these S.L.N. elements has been discovered. That Element has had many names across the races, but it is known to the galaxy at large as Synchrium.
This would be enough to make Synchrium an astounding element but it's only the start of the weirdness around Synchrium.

Utility

Orcs discovered Synchrium over a century ago and they still can not explain how it manages to break the otherwise immutable laws of physics. Once formed Synchrium can be fairly easily convinced to bond with metallic elements, Iron, Copper, Cadmium and Nickel being the most common.
This is where it gets strange, every molecule of any given compound of Synchrium behaves as if it every other molecule of that compound.
So if you hook a sample of SyFe³ to a signal generator and run a pulse of electric charge through it every other molecule of SyFe³ will experience that same charge. Over spans of thousands of light years, with almost no notable delay.

Manufacturing

Synchrium can only be made in a particle collider. The process involves combining atoms and then recombining the resultant atoms many times over with the intermediate stages being some of the shortest lived elements known.
The most prolific laboratories manage to make a few ounces a week.

Discovery

Synchrium has been discovered multiple times:

The Orcs were the first to discover Synchrium

The Elves discovered Synchrium next they actually discovered it twice, the first time they tried to cover up the discovery because Synchrium makes so little sense.

Kobolds discovered Synchrium 120 years after mathematically proving it existed, even they didn't expect the things it could do.

Humans discovered Synchrium by accident when they left the Luna Orbital Collider Array on over a long weekend.

Gnomes discovered Synchrium trying to prove Synchrium was impossible.

Dwarves discover Synchrium trying to build small artificial stars to power space craft

Aurians discovered Synchrium then ignored it for 50 years because it doesn't sparkle.