the crystal in the core of the planet is stable and rather large, however Shiira have learned how to grow smaller ones.
these smaller ones are instable and can not be used for most causes.
currently there are 2 known uses for a instable core crystal:
Shiira are currently also trying to learn more ways to use the core crystal by training a new kind of speciallists able to keep the core crystals more stable:
aside the planet based core crystal, there is a nother one, Ellectrose core crystal.
this version is found on the planet near the top of mountains, they seem to regenerate from time to time and seem to be a stable mix between the smaller core crystals and the ellectrose crystal.
these crystals are used to power engins and energy weapons in fighters and vehicles/ tanks.
If an instable core crystal loses control it will explode, turning everything in a 5 kilometer radius into crystal as destroy the ship it was stored on.