Selenium, elemental nonmetal halides

Aside from these three classes (species with unfilled inner subshells, with unpaired electrons, or with two different oxidation states of the same element), there are a number of colored inorganic substances about which generalizations may be set up only with difficulty. Among these are many of the elementary nonmetals, a large number of covalent salts (such as mercuric iodide, cadmium sulfide, silver phosphate and lithium nitride), a number of nonmetal halides (iodine monochloride, selenium tetrachloride, antimony tri-iodide, etc.), and the colored ions, chromate, permanganate, and Ce(H20) v, whose central atoms presumably have rare-gas structures. 

LithophiLes are rock-loving elements found predominantly in oxide minerals or as halides. SiderophUes or iron-loving elements are found mostly in the earths core, and chalcophiles are elements found in the earths crust in combination with nonmetals, including sulfur, selenium, and arsenic. 

---