Answer:
What does a stone become when in the water?
The most fabulous way to locate pots of gold
Passed from father to son and shared between brothers, its importance is unquestioned though it is used more by others.
It can be clear like water, but it burns like fire.
It's what light turns into in the night
As round as an apple. As deep as a cup. All the king's horses can't pull it up.