I've been reading a book entitled Salt: A World History. I know, it sounds a little odd, but I'm a unit study girl from way back so the idea of pivoting a study of history around this one element common to all cultures seems logical to me.
Anyway, there's one brief section I want to share that speaks to a theme we've talked about here from time to time - the human longing for beauty. From a chapter on mines controlled by the Polish Crown it says that at first, working the mines was basically a death sentence in slave conditions. Men would climb down 50 ladders and use hand tools to dig out the precious mineral. It was so hot that men worked naked. Horses that worked the mines spent their entire lives underground. In spite of all that, miners worked to improve conditions in small ways.
In 1689, the mines began offering miners daily Catholic services at their underground place-of-work. the miners of Wieliczka began carving religious figures out of rock salt. Three hundred feet below the surface, miners carved a chapel out of rock salt with statues and bas-relief scenes along the floor, walls, and ceiling. They even fashioned elaborate chandeliers from salt crystals.
Apparently you can still visit there today. It's really pretty amazing!