Actually, while
Fabricate would work,
Shatter does nasty things to crystaline beings, structures and objects and is much more available.
The normal process for mining salt involves soaking salt bearing rocks in water, so the salt dissolves and the rest of the rock stays behind. Then the water is spread in evaporating trays and left in the sun. What's left is chipped out of the trays and ground the the desired consistency.
Like I've said, for our game I'll just specify that the salt is inherently tainted with the blood of the creature it used to be, and completely unsuitable for normal use without extensive processing.
As for it's value? It isn't just a condiment or "food additive". It's necessary for life, a neuro-electrolyte. Soldiers used to get part of their pay in salt, and a man who "wasn't worth his salt" was one who wasn't worth keeping alive.
Look up the history of Salzburg some time. Two guesses how it got it's name, or what sort of trade was the foundation for its wealth.
Or, look at the New York Times articles on the Civil war (Disunion, in the Op-Ed pages), and the impact a salt shortage had on the Confederate war effort. Shortages of salt due to the blockade of European imports made it hard to preserve foods, so that even though the Southern states were huge agricultural producers, they were in a constant struggle to feed their armies.
Or do a bit of research on the "Great Hedge of India" (
Inland Customs Line - Wikipedia, the free encyclopedia ), erected to control the salt trade.
The history of salt is the history of the world.