Help! Terrible craving to eat dirt, just tasted a house plant...

Pica , or cravings for non food items are apparently common according to this article : http://www.babycenter.com/404_what-causes-pica-craving-and-consuming-non-food-items-during_1186643.bc

However, I am really surprised at how much I just want to take a big bite of dirt! Iron levels are OK, everything seems fine except this craviing. Now, looking for something healthy to eat that might satisfy this dirt craving, any advice?