system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Was Luke's light saber crystal synthetic?

If so, how does he learn to make them? Why is it green instead of red? Or did he find a natural crystal?
gpt
In Legends,  it was. We do not know about it in canon, but there's nothing in canon that indicates that the crystals can be made synthetically.

In fact, given that the same type of crystals are used to power the Death Star superlaser and the Empire is displacing civilians in order to access and mine out the crystals necessary for constructing the DS, it's rather lokely they can't be made synthetically, at least not up to the size the DS requires.