Zophis crystal

Zophis crystals were a type of kyber crystal from the world of Zoph. Long before the Clone Wars, some Jedi Padawans would travel to Zoph in order to seek Zophis crystals for use in the construction of their lightsabers, which would produce a devastating but unstable blade due to the crystals' unique resonance. Lightsabers made using Zophis crystals could carve through durasteel plating with ease, but suffered from vulnerability to fluctuations in power from their crystal core.

As the planet Ilum and its kyber crystals increased in prominence within the Jedi Order, the use of Zophis crystals declined. By the time of the Clone Wars, Zophis crystals were extremely rare and valued at 11,000 credits. Records still existed of the crystals' use in lightsabers, but with Zoph under the control of the Confederacy of Independent Systems, any attempts by Jedi to retrieve them would be met with hostility.

Behind the scenes
Zophis crystals were first mentioned in Rise of the Separatists, a 2019 supplement to Fantasy Flight Games' series of Star Wars roleplaying products.