Organic Living From the Ancient Zechstein Seabed For Body and Foot Soaks 100% Pure Super Concentrated Flakes First Choice Optimal Health Discussion: Pure Magnesium Flakes are highly-concentrated crystals of magnesium chloride sourced from the ancient Zechstein seabed in the Netherlands—nothing added and nothing removed. The magnesium flakes are extremely pure because the seabed lies 1,600 to 2,000 meters beneath the surface of the earth where it has been protected. Refresh your body and mind by using Pure Magnesium Flakes in a full bath or foot soak.