The table salt, the cheapest one is usually 99.8% sodium chloride NaCl, with ferrocyanides as anti-caking agents.
The thing is that in nature, the sea salt is never almost perfectly 100% NaCl.
Dead Sea salt has only 30.4% NaCl
While average ocean water salt has around 85% NaCl
The mineral content of the Dead Sea is very different from that of ocean water. The exact composition of the Dead Sea water varies mainly with season, depth and temperature. In the early 1980s, the concentration of ionic species (in g/kg) of Dead Sea surface water was Cl− (181.4), Br− (4.2), SO42− (0.4), HCO3− (0.2), Ca2+ (14.1), Na+ (32.5), K+ (6.2) and Mg2+ (35.2). The total salinity was 276 g/kg.
[26] These results show that the composition of the salt, as anhydrous chlorides on a weight percentage basis, was
calcium chloride (CaCl2) 14.4%,
potassium chloride (KCl) 4.4%,
magnesium chloride (MgCl2) 50.8% and
sodium chloride (NaCl) 30.4%. In comparison, the salt in the water of most
oceans and
seas is approximately 85%
sodium chloride. The concentration of
sulfate ions (SO42−) is very low, and the concentration of
bromide ions (Br−) is the highest of all waters on Earth.
https://en.wikipedia.org/wiki/Dead_Sea#Chemistry
The Himalayan pink salt contains around 97% NaCl and 3% for the other minerals - magnesium, etc.
So question - why did people choose to eat mainly NaCl ? ?