1) Halide mineral 
Antarcticite is an uncommon calcium chloride hexahydrate mineral with formula: CaCl2·6H2O. It forms colorless acicular trigonal crystals. It is hygroscopic and has a low specific gravity of 1.715. As its name implies, it was first described in 1965 for an occurrence in Antarctica where it occurs as crystalline precipitate from a highly saline bri...