Todorokite is a rare mineral compound that is primarily composed of manganese and can be found in metamorphic rocks. There are not many synonyms for this particular mineral, but some possible alternatives are braunite, cryptomelane, and hollandite. Braunite is another manganese mineral that appears in black and brown colors, while cryptomelane is a dark black mineral that is sometimes called potassium manganese oxide. Hollandite, on the other hand, is a black mineral that is composed of barium and manganese oxides. These minerals have slightly different physical and chemical properties but share some similarities with todorokite.