Hijiki seaweed is naturally green or brown in color when it’s hand-harvested by fishermen and divers in the wild. Before being packaged, it is boiled and then dried, and this process turns hijiki black. Like the other edible sea vegetables, hijiki is known for its dietary fiber and essential minerals like iron, calcium, and magnesium. What’s special about hijiki is it has a pleasant crunch and chewy bite after cooking. The taste is more earthy rather than oceany.