Professor here is a legend that you might find interesting
The Goose that Laid the Golden Egg and that artist that created ceramic eggs and covered them with gold and jewels so that folks would not break them open to remove the gold that was in the middle of the ceramic egg.
What is funny about that particular legend is that one can turn leadsulfied (galena) into gold using the ceramic egg method

and it is actually quite simple. The Egyptians used the method alot and the math for it does change the concept of nuclear physics abit. I have done this and it does work, it is just that the lead changes to bismuth first and then the bismuth changes to gold. And because it is an endothermic reaction it "does" require a long cooking time.
Here is what one needs: a charcoal forge, ceramic clay, slaked lime or very clean powered limestone (I used slaked lime), and a small chunk of Galena (lead sulfied). It turns out that limestone (calcium carbonate) is the philosopher's stone so the lime is critical for this process to work.
Place the leadsulfied chunk inside a small ball of lime and water. Then place the lime ball in a ball of ceramic clay and shape the clay into an egg shape that is about the size of a large goose egg. Cook in forge for a long time, you can not over cook it and the longer the better. I did it in this my old wood stove one winter when I had nothing else to do. You need to keep the egg temperature in the golden white color heat range.
And until somebody else does this

(Oh and admits that they did it under scientific conditions) the fact that I did it is not science. Ok?
love,
sunmystic