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Group III – Aloidi
NaCl
Very common
The Rock Salt or Halite occurs in cubic crystals often “hopper” and with rounded corners, usually colorless or white, sometime yellow, red, brown and even blacks; more rarely patchy irregular blue and purple; predominantly cubes and in massive sedimentary beds, but also granular, fibrous and compact.
Formation environments are sedimentary chemical deposits derived from the evaporation of water, mostly saline, in enclosed seas and in hot weather.
In ancient times it was known as “white gold“, a vital element, valuable as much as water. Salt has played a key role in human history since the dawn of time.
In ancient Egypt was the exclusive preserve of the Pharaohs, while the Roman soldiers constituted the “salary”, which takes its name from the salt.
The only way, along with the snow, for preserving food, salt was considered so valuable that, even today, in superstition, spill it brings bad luck. So much so that at the Last Supper by Leonardo Da Vinci there is a salt shaker on the table upside down, unequivocal symbol of impending disaster.
