Apatite is found in igneous, metamorphic and sedimentary rocks. Apatite is not one mineral but rather a group of phosphate minerals. In addition to blue Apatite, it can be found in as a yellow or green mineral. Apatite is used to manufacture of fertilizers. Although Apatite forms in hexagonal crystals as shown below, it is not considered a gemstone due to it’s lack of hardness.