Tuesday, 17 May 2022

Salt mining

Halite rock salt (NaCl)
Salt is a mineral made up of cube-shaped crystals composed of two elements, sodium and chlorine. It is translucent, colourless, and odourless. For centuries salt had a permanent place in the life of human beings. Salt was considered sacred, a gift from the Gods; it was used to confirm oaths and sacrifices. Salt served as money at various times and places, and the quest for salt has been the cause of warfare. Offering bread and salt to visitors is a sign of hospitality.

This made salt a valuable commodity throughout history.
Prior to industrialization, it was expensive and labor intensive to harvest the mass quantities of salt necessary for food preservation and seasoning. Mining salt caused rapid dehydration. Other problems related to accidental excessive sodium intake.
Entire economies were based solely on salt production and trade.
The 'Man in Salt' greets visitors at the Salzwelten Hallstatt Mine, Austria. In 1734 a corpse preserved in salt was discovered in the deposit.
At the Chehrabad Salt Mine, Iranian miners recently uncovered the 6th salt man to be found in the last 15 years. Salt men are ancient corpses killed or crushed in the cave and mummified by the extreme conditions. Hair, flesh and bone are all preserved by the dry salinity of the cave, and even internal organs have been found intact. The first salt man, dated to 300 A.D., was discovered in 1993, sporting a long white beard, iron knives and a single gold earring. In 2004 another mummy was discovered 50 feet away, followed by another in 2005 and a "teenage" boy later that year. The oldest of the salt men found is truly ancient and has been carbon dated to 9550 B.C.
Egyptians may have been the first civilization to preserve fish and meat with salt. Food that could be preserved was highly valuable. Recognizing the worth of preserving food, Egyptians turned to trade. The Egyptians did not export salt by itself, it was bulky and difficult to transport, but rather food that was salted, which transported easily without spoiling and had a value added. Ancient Egypt's trade started a 4000 history of trade involving salt and food.

Boiling brine into pure salt in China.
In the Iron Age evaporated salt was obtained by boiling seawater or brine in clay pots over a fire. Roman salt making entailed boiling seawater in large lead-lined pans. In ancient Rome, salt on the table was a mark of a very rich patron; those who sat nearer the host were "above the salt," and those less favored were "below the salt". Roman salt mining was often done by slave or prison labor, and life expectancy was low.
Malta Roman salt flats

Ancient Roman Glass Salt Dishes
The Roman historian Pliny the Elder stated as an aside in his Natural History's discussion of sea water, that "[I]n Rome ... the soldier's pay was originally salt and the word 'salary' derives from it ..."

Roman Salt Pans in Hortales.