Aragane no Ko

Aragane no Ko is a Manga/Manhwa/Manhua in (English/Raw) language, Action series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.com fastest updating comic site. The Summary is

In a world where life revolves around “stones”, the mineralogist Akeboshi visits an underground village and meets a boy whose left leg has been petrified. What’s the secret behind this boy who’s looking for a man wearing an earring with three lines…?! The teacher and his apprentice set out on a journey where they’ll polish one another and, hopefully, save the latter’s family!