Salt isn't made from salt water, it is already present in the salt water. If you were to heat up the salt water, or put it on an evaporating dish, after a while, all the water will be gone and you'll be left with salt crystals. Industrially sea water is 10times concentrated to get salt crystals.
because crystals and gems have salt in them and they take a little bit longer to make than normal rock. After they become igneous rock, they would most likley go in water and and form from salt. that is the way the crystals and gems are made