Kyber crystal

Lightsaber
A lightsaber
Plot element from the Star Wars franchise
Production company	Lucasfilm
First appearance	Star Wars (1977)
Created by	George Lucas
Genre	Science fiction
In-story information
Type	Energy sword
Function	Fencing Stabbing Cutting Welding Melting Heating Shielding Fighting Burning Lighting Throwing
Affiliation	Jedi Sith Knights of Ren

A lightsaber is a fictional energy sword featured in the Star Wars universe. A typical lightsaber usually consists of a metal hilt (usually around 11 inches (28 cm) in length) that projects a brightly lit energy blade (usually around 3 feet (91 cm) in length). The lightsaber is the signature weapon of the Jedi Order and their Sith counterparts, both of whom can use them for close combat, or to deflect blaster bolts. Its distinct appearance was created using rotoscoping for the original films, and with digital effects for the prequel and sequel trilogies. The lightsaber first appeared in the original 1977 film A New Hope and has since appeared in every Star Wars movie. In 2008, a survey of approximately 2,000 film fans found it to be the most popular weapon in film history.

In its most prominent showing, the lightsaber's energy blade can cut, burn, and melt through most substances with little resistance. It leaves cauterized wounds in flesh, but can be deflected by another lightsaber blade, or by energy shields. The blade has even been used as a tool to weld metal substances. Other times, the lightsaber has been shown to cause bleeding wounds in the flesh, sometimes accompanied by burns. Some exotic saber-proof materials have been introduced in the Expanded Universe. An active lightsaber gives off a distinctive hum, which rises in pitch and volume as the blade is moved rapidly through the air. Bringing the blade into contact with another lightsaber's blade produces a loud crackle.

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Wikipedia