Reikisekka

Reikisekka (靈氣石化, Literally meaning: Spiritual Energy Fossilization) is a kekkei genkai of Shōseki clan which allows its wielder to solidified chakra with their bloods.

Overview
Unlike most kekkei genkai in the world, Reikisekka is not originated from the nor. It was first manifested by a Shōseki a few centuries after chakra was blessed to human kind. Similar to how Ōtsutsuki evolved their eyes to Byakugan so they can seek out chakra and God Tree, Shōseki went through an internal evolution that caused their bloods to solidified chakra upon contact. Initially, only a few selected members possessed it but after several generations, most if not all Shōseki were born with it.

The reason of this miraculous evolution was unknown but Tengen Shinshō, one of the greatest mind in his era postulated that it was the will of god. It was later revealed to be a false statement. Tengen simply said that to befriend them in hope to get access to the fruits of their kekkei genkai, the Chakra Stones. The interaction between their blood and chakra gives birth to petrified chakra rock that appears like fossil, hence the name Chakra Stones and Reikisekka.