You hammer them until they're all circles (or in a specific pattern).
In Link and the legend of Zelda, Phantom Hourglass, you get the hammer in the isle of ruins, or the island of the dead.
On the island of ruins
you get the third precious metal for the phantom sword.
isle of ruins in the king's pyramid
youtube everybody!check there!
you have to get the northeastern seachart that's how to go to that place
u get it from the isle of ........... Death? I forgot the one near the isle of ruins in the maze
You get the hammer in the Golden Pryimid temple thing on the Isles of Ruins which is in the south-east part of sea.
One og them is in the temple of frost another one is in the temple of goron then the last one is the isle of ruins
On the island of ruins
A flag type thing: __ | | |/\|
King Mutoh is on the isle of ruins, but you need the 4th sea chart (and the regal necklace which someone gives to you) to get there. he is in the biggest golden temple.