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 | |
| IMPORTANT ERRATA | 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 • Gamma HQ • Deep Space 15 • Starbase Unity • Finnea Prime • Finnean Convergence Zone |
| NOTABLE STARSHIPS | USS Black Hawk |