I know there have been various suggestions previously regarding a machine like this. However I do not think it as ever been answered (if it has sorry for the dup - please point to it if you can).
@james What I am suggesting is a machine that you can put any crafted material into (such as a brick, or compacted silt) and break it back down to the original components (stone, compact clay, mud and ash for brick or regular silt). Then if you wanted to take the compact clay back to regular clay just put it in the machine again.
You could have it need spark and maybe coils?
My reason for this is just that sometimes you make more than you need of something and are not really going to use it again. Why not have the base materials that you could use for something else?
What do others think?