Minerals we consume in our daily diet aren't actually rocks, but some of them are not that different from "rocks" in a technical sense! Minerals are inorganic elements that occur naturally in our environment. A rock, on the other hand, is often a combination of multiple minerals that have been crystallized and compressed over time. The minerals that we eat have been converted into a bio-available form by plants, making it possible for us to digest and absorb them.
Many consider iodine to be no more than a gentle antiseptic or first-aid substance, since you rarely see it in the 'nutritional requirements' section on a food label. This natural element, however, is not only required by your body, it is vital to your overall health. Iodine deficiency is a surprisingly common condition that's becoming ever-more present in today's society.