"And SALT is the oldest and longest lasting commodity"
Ever poor water on salt. Dissolves doesn't it. Your ignorance is astounding.
Do you REALLY supposed that nations who relied on salt for their wealth wouldn't store it carefully and away from water contact?
The ancient Romans not only paid their solders in salt, for a period of time, but the Senate manipulated the price of salt, in order to help fund the Punic Wars. The very word SOLDIER comes from the French word solde, which comes from the Latin word sal....SALT! Even the word salary comes from the word ............SALT. And then there's the term worth his salt. Can you guess where that comes from?
The Chinese, Indians, Germans, Medieval Italians, to mention but a few, all based some part or at times all of their economies on SALT. And since you have no idea how salt has been made, from ancient times, even IF a lump or a rock ( yes, ROCK!) of salt gets wet, when the sun shines on the puddle, it evaporates and do you know what is left, after evaporation? No? SALT ! :-)