Hawleyite is a rare sulfide mineral in the sphalerite group, dimorphous and easily confused with greenockite. Chemically, it is cadmium sulfide, and occurs as a bright yellow coating on sphalerite or siderite in vugs, deposited by meteoric water. It was discovered in 1955 in the Hector-Calumet mine, Keno-Galena Hill area, Yukon Territory and named in honour of mineralogist James Edwin Hawley (1897–1965), a professor at Queen's University in Ontario, Canada.