Birythium is an element found only in the Gamma Quadrant. It is not a common element, known to appear only on one world, an unnamed M-class world where Captain Benjamin Sisko was introduced to the Jem'Hadar.
In 2390, birythium became an export in the Mellon system.
| THE GAMMA QUADRANT | |
| THE QUADRANT | Task Group Belvedere • Gamma Quadrant Map • Finnean Convergence Zone Map |
| NOTABLE POWERS | The Dominion • Unknown Power G90B • The Consortium • The Guardians • Gamma Quadrant Species |
| NOTABLE PLACES | Gamma Command • New Bajor • Deep Space 15 • Finnea Prime • Finnean Convergence Zone |
| NOTABLE STARSHIPS | USS Black Hawk-B • All Starships in Quadrant |
| GAMMA COMMAND | Gamma HQ • TG Archimedes • TG Belvedere • TG Sentinel • TG Sonzwaphi |