Given how the overwhelming majority have white cores, I imagine nearly all crystal species capable of being used in lightsabers would create them. It might take years or even decades to obtain one of the species that generates a black core.
@Optimusprimebumblebee "Neo Astral-X" 123 I mean the core of the saber blade, not the outside glow, black and white cores have all the same colors, just different insides of the blade
