Himalayan salt might not be agood choice, if you are looking for pure salt. Pure salt is clear, and in powder form is white. Himalayan salt is pink due to dead microbes in the salt. It also is known to have many metal species in it as impurities, including chromium, iron, zinc, lead, and copper.
These days it is a very common salt, and also is affordable, but frankly as someone that cooks i avoid this salt because I don't trust the sourcing. It is produced in Pakistan, not really from the Himalayan mountains as advertised.
You are correct that it is mined in Pakistan, but the mines are located in the foothills of the Himalayan Mountains. Its a massive span of area. I find the mines and the sustainable mining practices they allegedly follow to be quite fascinating.
I would be curious to know about these "dead microbes" I could not find anything that mentioned this. I was under the understanding that it was the presence of trace minerals that caused the salt to be pink? I haven't really investigated it too intensely though. In all honesty, the ancient history of this salt being used for healing is really what got me using it. :)
Thank you for your response to spbeckman - whose input is also acknowledged here, but I think both of your questions and concerns might well be addressed in the book I cited in my comment above, Water & Salt, The Essence of Life, by Dr. Barbara Hendel, MD and biophysicist, Peter Ferreira, available at http://www.americanbluegreen.com/