apatite, A member of the phosphate group of minerals, the world’s major source of phosphorus, found as variously coloured, glassy crystals, masses, or nodules. Much of it has a chemical composition approximating Ca5(PO4)3(F,Cl,OH). If not for its softness, apatite would be a popular gemstone; some of the material found is clear, but it is fragile and difficult to cut and polish.
apatite Article
apatite summary
Learn about the properties of apatite and its use as a mineral and gemstone
Below is the article summary. For the full article, see apatite.