In a thatched-roof workshop on the Filipino island of Bohol, 68-year-old Romano Apatay uses a scoop made from an empty shell to pour brine into a series of brown, orb-shaped clay pots suspended over a wood fire. When the pots begin to crack, he removes them from the flames. Once cooled, he turns them over and carefully breaks open their brittle outer shell with his fingertips, revealing a white sphere that's one of the rarest salts on Earth.