Apatite

The name apatite comes from the Greek word apatein, meaning to deceive, because it’s often mistaken for many other minerals. Apatite is actually a group of phosphate minerals, usually referring to fluorapatite (if fluorine is the primary ion), chlorapatite (if chlorine is the main ion), and hydroxylapatite (if the hydroxyl group is dominant). Apatite is the defining mineral for value 5 on the Mohs scale.