if you want your crystal to glow, consider using a tritium keychain. They're available in a number of colors and are very small.

From what I understand, they're not dangerous though they are radioactive. They emit a glow and will do so for a number of years (10 to 20).

Despite their alleged safety, I'm not able to find any on-line retailers who sells them.

I just think it would be cool to have a glowing crystal core for someone's saber.

thanks for reading!