What are these crystals on my lunch meat?

[Ms2001]

I opened a few packages of sliced sandwich meat and put them in the fridge, unsealed. Now, several days later, the chicken and ham have clear little crystals on the exposed parts (but the turkey doesn’t). Daredevil that I am, I washed them off and ate it anyway.

The same areas of the meat are also somewhat dry and hard, which makes sense, but what are the crystals?

[Q.E.D]

My guess is that it is salt. Many deli meats, particularly ham and cured meats, are fairly high in salt. As the meat dries out, the salt probably comes out of solution and forms crystals.