When first placed, they are simply called Copper Blocks, but after enough time as passed, they become Exposed Copper Blocks.
This will keep them from oxidizing past whatever stage they're currently on.
The same phenomenon has been implemented in Minecraft.
But there are some out there that are just now getting back into the game, after waiting through the original Caves and Cliffs Part 1 Update.
They require the use of a pickaxe and is not uncommon.
I think this is final.