1. Any of a group of natural, variously colored calcium phosphate minerals containing fluorine, chlorine, or hydroxyl. These compounds form hexagonal crystals and are components of bones and teeth, are a source of phosphorus for plants, and are used in the manufacture of fertilizers.
2. See fluorapatite.
[From Greek apatē, deceit (from its often being mistaken for other minerals).]
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2019 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Indo-European & Semitic Roots Appendices
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