Wouldn't be too much of an uptune to show how heavy in kg the mineral is
inside of a forge if not too many minerals were in forge.
Dealing with materials, I'm willing to bet you're a merchant, with access to a
merchant belt I hope, one that can be fitted with a "weigh" command that works
on forges too.
If you want that option from your forges, buy a masterforge, they do that
already.