Well, this certainly looks like a K’tonian artifact but if you notice the grooves on the bottom, that means that this was actually made on a Jiyong potters wheel as an imitation of the K’tonian style of pottery. This is a replica, albeit a 700 year old, very good replica. I do happen to know a buyer who would be willing to pay you for it.
On the road up Dethl Mountain, you will encounter the guardian, Rustus, a goron Pyro Mage. only those who can take the heat will withstand him. to defeat him, one must use a goron's worst enemy: water