Halite is NaCl. I think sylvite, potassium chloride (MOP) is what they mine around the world, mostly
http://en.wikipedia.org/wiki/Potassium
SOP, potassium sulphate is what they want to extract from Lake Disappointment.... worth more than KCl too, I think.
Yes, to see the disappointments evaporate, the NaCl precipitated out with the Mg, Ca ions etc.... purify the K2SO4 through series of evaporative ponds.
