Have you heard of a Slate Gray Nevus? Slate Gray Nevi are a type of pigmented birthmark found on many newborns, most often located on the lower back and buttocks. The spots occurs due to entrapment of melanocytes (pigment cells) in the dermis of the developing embryo, when the cells have failed to reach their proper location in the epidermis. This birthmark is most common in infants of East Asian, Polynesian, Indonesian, and Native American decent. Slate Gray Nevi were previ