Ferroselite is a rare mineral consisting of iron selenide, which has a dark gray color and metallic luster. However, there are several synonyms for this mineral that can be used in different contexts. One term is iron selenide, which is an accurate description of its chemical composition. Another synonym is Selite or Selenite, which comes from its selenium content. Some people may also refer to ferroselite as iron(II) selenide or FeSe, which are its respective chemical formula and prefix. Overall, whether you call it Ferroselite, Selite, or Iron selenide, this mineral remains a fascinating discovery in the world of geology and mineralogy.