First discovered in an impact crater on Mars in 2101, Helidyte is a mineral compound that when exposed to Nitrogen decomposes releasing high levels of Helium. With both XEM and QS reactor technologies requiring vast amounts of Helium the mineral held great potential as a fuel source. Unfortunately all that existed was a 12 gram sample.
With the Helium shortage on Earth a mining expedition was started aimed at the red planet to see if they could find more Helidyte. The operation however never made it to Mars as large deposits of Helidyte were identified in the Kuiper Asteroid Belt in 2118. This discovery led to the establishment of the Titus Mining Colony and the Luna Chorda refining complex on the moon in 2122.
Helium extraction from Helidyte was a boon to Earths tech industry leading to significant advancements Quantum Static power generation which in turn led to advances in other high energy technologies such as LEAP.
After the Exodus 2179 humanity is slip between two galaxies. In Draco Tao on humanities new home world of Solum there was no longer a Helium shortage however Helidyte remained a critical element in energy generation until 2230. It was simply more efficient transport and refine Helidyte than to handle Helium itself. After 2230 many colonies moved to solar power or localized Helium extraction but Helidyte was still needed for ships and space stations. In the Milky Way Helidyte is still a high value commodity in the outer colonies but is no longer used on Earth.
Helidyte is a gray brittle shale-like mineral. Raw Helidyte breaks down rapidly when exposed to Nitrogen producing Helium 4 and Beryllium nitride as a byproduct.