The Crystal Release (晶遁, Shōton; English TV "Crystal Style") is a specialized field of Ninjutsu that can create crystal, (providing the user with an unlimited supply of melee weapons,) as well as manipulate already-existing Crystals and crystalline structures. It is seen only in the anime, and its only known user is a woman called Guren. This element appears to regularly use the Ram hand seal.
According to rumors that Tsunade had heard, Crystal Release can crystallize any substance. Using Crystal Ninjutsu, the user can crystallize any physical material and even the moisture that is present in the air around them, turning them into a weapon. In the case of human targets, Crystal Release can solidify its targets down to the cellular level, imprisoning and even killing the victim should the crystal ever be struck, reducing the mass of crystal and the victim down to crystalline dust.
According to Kakashi's observations, Earth Release, Water Release and Wood Release are all useless against the Crystal Release style: Because the Earth, Water and Wood styles all have physical mass, they can be crystallized, and then turned against the Crystal user's opponent. The Crystal style does this by influencing the arrangement of minerals and the structure of molecules. Liquid, mineral or organic, if it has physical mass, then the Crystal style can effect it, (thought it has not been seen used on metal.)
The only apparent weakness of the Crystal Release is that it cannot crystallize either raw energy or chakra as they have no physical mass to crystallize, allowing a person with either energy-based jutsu, such Wind Release, Fire Release and Lightning Release, or good chakra control to properly counter it. Crystal Release is also suseptable to a specific soundwave frequency; because crystal requires a very precise build-up of molecules, the proper soundwaves can break down the build-up before the crystal can properly form. Rinji, taking advantage of this weakness, used his Ninja-Bats to counter Guren's Crystal Release.