Kyber crystals are rare minerals that many believe to have a special connection to the Force. Their unique molecular formation resembles organic material, which helps the crystals contain, focus, and amplify energy like few other known materials. This is the reason that they are most commonly used in lightsabers. Although every lightsaber schematic is different, the weapon must contain at least two crystals: one to convert the energy from the power cell into plasma energy, and a second to focus the raw power from the first into a safe and manageable stream. These smaller shards serve as the secondary focusing crystals.
Shards of kyber crystals have also been used in the energy production industry and in jewelry, although their cost in these industries is normally prohibitively high due to their rarity. It is rumored that these crystals grow naturally in many places across the galaxy, but the locations of these caves are secrets zealously guarded by the many religious groups that revere them.