How many crystals can be used in a lightsaber?

How many different kinds? A bunch. How many at once? Only one. Its never really explained, but the way I picture it is that its like trying to screw to light bulbs into one lamp. It just dosent work. read more

In most cases, one. It’s the most stable, predictable and popular combination. A single kyber crystal is enough to power majority of lightsabers. Occasionally, a lightsaber will use a type of crystal other than kyber, and in those cases more crystals may need to be used. read more

A lightsaber crystal was a term used to describe any variety of crystals, gems, stones, or other objects used as the focus in the construction of a lightsaber. At the heart of every lightsaber was a set of crystals that resonated to produce the efficient, powerful blade. read more

A lightsaber crystal is colorless until first attuned and connected to a Jedi -- at which times it glows either blue or green or, in some rare instances, another shade. From that point on, it retains that hue. read more