1. a mineral composed of calcium phosphate, typically occurring in hexagonal crystals and used in fertilizers and as a gemstone
Usage: geology; mineralogy

Examples

• Apatite is one of the most common phosphate minerals found in the Earth's crust.
• The geologist identified apatite crystals in the rock sample under the microscope.
• Apatite is mined extensively for use in phosphate fertilizers.
• Some varieties of apatite are transparent enough to be cut and polished as gemstones.
• The blue-green apatite specimen was a prized addition to the mineral collection.