Apatite (CaF) (fluorapatite) doubly-terminated crystal in calcite
General
Category
Phosphate mineral
Formula (repeating unit)
Ca5(PO4)3(F,Cl,OH)
IMA symbol
Ap[1]
Strunz classification
8.BN.05
Crystal system
Hexagonal
Crystal class
Dipyramidal (6/m) (same H-M symbol)[2]
Space group
P63/m (no. 176)
Identification
Color
Transparent to translucent, usually green, less often colorless, yellow, blue to violet, pink, brown.[3]
Crystal habit
Tabular, prismatic crystals, massive, compact or granular
Cleavage
[0001] indistinct, [1010] indistinct[2]
Fracture
Conchoidal to uneven[3]
Mohs scale hardness
5[3] (defining mineral)
Luster
Vitreous[3] to subresinous
Streak
White
Diaphaneity
Transparent to translucent[2]
Specific gravity
3.16–3.22[2]
Polish luster
Vitreous[3]
Optical properties
Double refractive, uniaxial negative[3]
Refractive index
1.634–1.638 (+0.012, −0.006)[3]
Birefringence
0.002–0.008[3]
Pleochroism
Blue stones – strong, blue and yellow to colorless. Other colors are weak to very weak.[3]
Dispersion
0.013[3]
Ultraviolet fluorescence
Yellow stones – purplish-pink, which is stronger in long wave; blue stones – blue to light-blue in both long and short wave; green stones – greenish-yellow, which is stronger in long wave; violet stones – greenish-yellow in long wave, light-purple in short wave.[3]
Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ion, respectively, in the crystal. The formula of the admixture of the three most common endmembers is written as Ca10(PO4)6(OH,F,Cl)2, and the crystal unit cell formulae of the individual minerals are written as Ca10(PO4)6(OH)2, Ca10(PO4)6F2 and Ca10(PO4)6Cl2.
The mineral was named apatite by the German geologist Abraham Gottlob Werner in 1786,[4] although the specific mineral he had described was reclassified as fluorapatite in 1860 by the German mineralogist Karl Friedrich August Rammelsberg. Apatite is often mistaken for other minerals. This tendency is reflected in the mineral's name, which is derived from the Greek word ἀπατάω (apatáō), which means to deceive.[5][6]
^ abcdefghijkGemological Institute of America, GIA Gem Reference Guide 1995, ISBN 0-87311-019-6
^According to Werner himself – (Werner, 1788), p. 85 – the name "apatite" first appeared in print in:
Gerhard, C.A., Grundriss des Mineral-systems [Outline of the system of minerals] (Berlin, (Germany): Christian Friedrich Himburg, 1786), p. 281. From p. 281: "Von einigen noch nicht genau bestimmten und ganz neu entdeckten Mineralien. Ich rechne hierzu folgende drei Körper: 1. Den Apatit des Herrn Werners. … "(On some still not precisely determined and quite recently discovered minerals. I count among these the following three substances: 1. the apatite of Mr. Werner. … )
Werner described the mineral in some detail in an article of 1788.
Werner, A.G. (1788) "Geschichte, Karakteristik, und kurze chemische Untersuchung des Apatits" (History, characteristics, and brief chemical investigation of apatite), Bergmännisches Journal (Miners' Journal), vol. 1, pp. 76–96. On pp. 84–85, Werner explained that because mineralogists had repeatedly misclassified it (e.g., as aquamarine), he gave apatite the name of "deceiver": "Ich wies hierauf diesem Foßile, als einer eigenen Gattung, sogleich eine Stelle in dem Kalkgeschlechte an; und ertheilte ihm, – weil es bisher alle Mineralogen in seiner Bestimmung irre geführt hatte, – den Namen Apatit, den ich von dem griechischen Worte απατάω (decipio) bildete, und welcher so viel as Trügling sagt." (I then immediately assigned to this fossil [i.e., material obtained from underground], as a separate type, a place in the lime lineage; and conferred on it – because it had previously led astray all mineralogists in its classification – the name "apatite", which I formed from the Greek word απατάω [apatáō] (I deceive) and which says as much as [the word] "deceiver".)
^"ἀπατάω". Logeion. Archived from the original on Feb 22, 2023. Retrieved Feb 22, 2023.
^"Fluorapatite mineral information and data". mindat.org. Retrieved 30 January 2018.
Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ion, respectively...
Lead apatite is a generic name for apatite-structure materials that contain lead as the divalent cation. A Copper-doped lead-apatite has been proposed...
hydroxylapatite) (Hap, HAp, or HA) is a naturally occurring mineral form of calcium apatite with the formula Ca5(PO4)3(OH), often written Ca10(PO4)6(OH)2 to denote...
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Bone mineral (also called inorganic bone phase, bone salt, or bone apatite) is the inorganic component of bone tissue. It gives bones their compressive...
scratch the given material. For example, if some material is scratched by apatite but not by fluorite, its hardness on the Mohs scale would be between 4...
the country rock. Apatite is by far the main gangue mineral while other gangue minerals are tremolite-actinolite and calcite. Apatite is at places evenly...
occurring impurity in apatite generates hydrogen fluoride as a byproduct during the production of phosphoric acid, as apatite is digested by sulfuric...
mineral hydroxyapatite. Apatite is a hard, insoluble compound. Acid (H+), produced especially after a high-sugar meal, attacks the apatite: Ca5(PO4)3OH(s) +...
Primary mineralogy is highly variable, but may include natrolite, sodalite, apatite, magnetite, barite, fluorite, ancylite group minerals, and other rare minerals...
Citrate is a vital component of bone, helping to regulate the size of apatite crystals. Because it is one of the stronger edible acids, the dominant...
albite, lepidolite, gem tourmaline, beryl, spodumene, amblygonite, topaz, apatite, and fluorite, which may partially replace some of the minerals in the...
Nelsonite is an igneous rock primarily constituted of ilmenite and apatite, with anatase, chlorite, phosphosiderite, talc and/or wavellite appearing as...
driest. Reconstruction of tropical sea surface temperature from conodont apatite implies an average value of 30 °C (86 °F) in the Early Devonian. Early...
S2CID 129179725. Harlov, D.E.; et al. (2002). "Apatite–monazite relations in the Kiirunavaara magnetite–apatite ore, northern Sweden". Chemical Geology. 191...
throughout the canyon. In another 2008 study, Rebecca Flowers reported on apatite (U-Th)/He thermochronometry results suggesting that parts of the Grand...
Main operations are the mining and processing of mines and processes apatite-nepheline ore from the Khibiny deposit. Products are marketed locally and...
Nigel C.; Popov, Leonid E.; Fischer, Woodward W. (1 March 2018). "A paired apatite and calcite clumped isotope thermometry approach to estimating Cambro-Ordovician...
phosphate, in a chemical arrangement known as bone mineral, a form of calcium apatite. It is the mineralization that gives bones rigidity. Bone is actively constructed...
the spontaneous growth of bone-like apatite nuclei on the surface of biomaterials in vitro. Therefore, the apatite formation on the surface of biomaterials...
The acid is also a by-product of the production of phosphoric acid from apatite and fluoroapatite. Digestion of the mineral with sulfuric acid at elevated...
Vanadinite is a mineral belonging to the apatite group of phosphates, with the chemical formula Pb5(VO4)3Cl. It is one of the main industrial ores of...
minerals containing little iron or magnesium, such as wollastonite or apatite, were included in the femic minerals. Cross and his coinvestigators later...
Logan, Terry J.; Ryan, James A. (1993). "In situ lead immobilization by apatite". Environmental Science & Technology. 27 (9): 1803–1810. Bibcode:1993EnST...