A Golden door is a door with strength between a Wooden and Iron door.
It is stronger than wood in the that:
- It requires at least a stone pickaxe to mine
- Baby villagers cannot open it (though adults still can)
- It has only a 10% to be broken down by zombies on normal, and 50% on hard
- More blast resistance
- It cannot be burned (obviously, as it's made of gold)
It is weaker than iron however, in that:
- It doesn't need a button to open
- Adult villagers can open it
- It can be broken down by zombies, and zombie pigmen
- Less blast resistance
- it can be mined quicker
It is most useful in the Nether, as some dead Zombie pigmen will yield gold nuggets, allowing you to make a fire proof door. They can also be found in some doorways in Nether fortresses.