No copper! The gracious Ball family, my hosts for the project, took turns on the bellows for a bit more than an hour. I pulled this lump from the furnace, still hot, a couple of hours after we ran it. It looked promising, but when I cracked it apart, it was only glassy slag, a purple like the original mineral. It stank powerfully like sulphur while it was still hot.

There is good news, however. Assuming that this ore is really is chalcocite, the fact that it vitrified means we achieved at least 1130 C, which means the furnace is hot enough for the reduction and fusing of copper oxide. The problem, I imagine, is that the first stage roasting was far from complete. Oxygen will leave elemental copper in favor of the carbon of  charcoal- sulphur, however, will hang onto the copper. To try again, I can roast what I have left more thoroughly. Also, I may have found small bits of malachite, which I believe is easier to smelt from, by another mine. Not vanquished yet!