In my other suggestion I mentioned "Construction Blocks". That suggestion is a little unlikely, but if any part of it made it into the game I would want it to be Construction blocks.
Construction blocks would simply have twice the strength of normal blocks. The entire map, unless the map-maker specifies, would be made of regular blocks.
Construction blocks enter your backpack through a certain task, similar to how the MMG and RPG will work.
Now, there are several options available.
A: Players must mine up construction blocks.
B: Players spawn with them but must collect more by mining them
C: Players spawn with them, can mine them, and can get them from the tent.
Please vote!