When a penguin wears this item by itself, with nothing else and dances with it, the penguin will start hitting a golden anvil with a hammer. The penguin may however wear a Ninja Mask and still be able to use the special dance.
There is a team named "Goldsmith Force" who wear the Goldsmith apron and fix valuable things in the Club Penguin webshow "WaddleOn". The team is first shown in episode #9. They are similar to the "Blacksmith Force", except they fix valuable objects like golden trophies, unlike the Blacksmith Force.
A penguin using the Goldsmith Apron with the Ninja Mask.