Apatite for Knowledge
Apatite's name comes from the name of the Greek goddess, Apate, the personification of deceit. That's because it comes in a rainbow of colors and was often confused with other gems. While attractive, apatite is soft and brittle, making it more popular as a collector's gem than as a gem for jewelry. Its most notable use is as an index mineral on the Mohs scale. Because its hardness is relatively consistent, it sets the standard for having a hardness of 5.