Apatit

Part of speech: noun

Definitions

1. A calcium phosphate mineral that forms crystals in rocks and is a major source of phosphorus used in fertilizers
2. A hard crystalline mineral composed of calcium phosphate, found in igneous and metamorphic rocks and valued for its phosphorus content
3. The name of a phosphate mineral group whose crystals occur in many rock types and are mined for phosphorus-rich fertilizer production

Etymology: Apatite was long confused with other gemstones. Green specimens could pass for beryl or emerald, and yellow or blue ones for topaz or aquamarine. The German mineralogist Abraham Gottlob Werner gave it a name drawn from the Greek "apatē", meaning deceit or trickery. The name records that confusion. The mineral is a calcium phosphate, and its chemistry is more significant than its looks: it is the main natural source of phosphorus in rock. Its hydroxyl form, hydroxyapatite, is also the mineral that forms the hard structure of bone and tooth enamel.