Holick has a solution--limited direct exposure to the sun--that infuriates many dermatologists worried about the skin cancer risk. (A far better idea, they say: Take a supplement.) In 2004 he published his book The UV Advantage, touting the benefits of sunexposure, and was kicked out of the BU dermatology department, where he previously held a joint appointment.
Initially, it is a soft, foul-smelling matter that floats on the ocean but through exposure to thesun and the salt water over years it turns into a smooth lump of compact rock which feels waxy and has a sweet smell.