Hello Mojang I need to tell ya smth. What i am reporting is not a bug, it is a Task you have to complete. You made two little mistakes about gold:

1) Gold Horse Armor is stronger than Iron Horse Armor
2) Gold Pickaxe can't mine Gold ore
3) Gold Pickaxe can't mine Gold Block

Did you want it to programm it like this or did you really make a mistake, because if gold is weak why should gold horse armor be stronger than iron horse armor?

P.S: I don't know how to choose issue types so i am sorry that i said that this is a bug. This is a task