Apatite minerals, are often mistaken for many other minerals. Apatite is usually green, but can be blue, yellow, purple, or brown. Collector specimens! Apatite is the name of a group of phosphate minerals with similar chemical compositions and physical properties. Apatite occasionally occurs as well-formed hexagonal crystals in hydrothermal veins and pegmatite pockets. These crystals often have a very high clarity and a vivid color.