I had a gf to crave some of these things you mentioned, for example: red clay dirt, frost from the fridge(i use to tell her not to eat that poison ice) she would go and search for people who had refrigs with that type of ice---strangers and all. The one thing that really grossed me out is she craved corn starch(she would literally put a straw in a box of corn starch and suck it out)!
The one weird craving I had when I was pregnant with my daughter, was I would eat candy apples with peanut butter on them.
