I understand you that you want to make something like Minecraft, i also like this kind of game. But doin't "core" mechanic is quite hard to do right. It may work now for you but then when you would like to add more chunks you will realize that you don't have optimalized code and you need to rewritte it from ground.
So i would recomend to find some working core system (blocks) and then you can and your custom crafting, monsters, etc...