Lava Release

is a nature transformation kekkei genkai , a combination of fire and earth. Whereas most kekkei genkai are largely identical between users, Lava Release has a variety of forms depending on who's using it.

Forms

 * Molten rock, both in solid and liquid states, is created by Son Gokū and its jinchūriki.
 * Acidic mud is created by Mei Terumī of Kirigakure, a form unique to her. In the anime, it is initially depicted as molten rock.
 * Corrosive quicklime is created by several Iwagakure shinobi. In the anime, it is also used by Kyūsuke of Amegakure.
 * Vulcanised rubber, which is strong against Lightning Release, is used by Dodai of Kumogakure. Sasuke Shinden notes that this form is in fact common among Kumo's leadership. Karyū also uses this version.
 * Volcanic ash is created by Kurotsuchi of Iwagakure. She also uses its quicklime form.
 * In Gaara Hiden, melting flames are created by Etoro Konjiki of Ishigakure.

Trivia

 * There is a subtle difference in the meaning of the kanji used for this kekkei genkai. Although both mean "to melt", the kanji with the radical (熔) is outdated and means "melting with fire", whereas nowadays the kanji with the  radical (溶) is normally used. Mei Terumī's Lava Release: Melting Apparition Technique, which utilises a strong acidic fluid, is the only Lava Release technique written with 溶. This, along with Jin no Sho stating that Mei's Lava Release kekkei genkai can only be used by her, indicates a difference between 溶遁 and 熔遁.
 * In Sha no Sho, the "water" kanji is used in Rōshi's entry, whereas in the glossary, the "fire" kanji is used. In Jin no Sho, only the "fire" kanji is used for Rōshi's Lava Release.