Where does salt come from?

sea salt

   Salt comes from mines, from wells, from springs, from salt lakes, and from the sea.
   The tunnels and rooms of a salt mine sparkle as if they had been dug through ice. Miners, using drills, cut the solid salt away in great glistening chunks. Then power shovels scoop it up and load it into little railroad cars which haul it out of the mine.
   A salt well is very different from an ordinary well. It is a hole in the ground all right, but pumps force water down into it! This water dissolves salt which is buried in the earth. Then the salty water, called brine, is pumped back out and boiled in pans. The water evaporates, leaving the salt in the pans.
   Sometimes an underground stream flows through a bed of salt. When it comes to the surface it is a salt spring. Brine from these springs and from salt lakes and from the sea, can be boiled to make salt. More often. the naturally salty water is allowed to stand in the sun in big shallow reservoirs or ponds. The sun dries the water away, and the salt stays behind.
   In the old days salt was scarce. Only those people who lived near the sea could get it easily. But everybody needed it to preserve meat and fish because they had no refrigerators in those days. Salt was so valuable that it was used as money in some places