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Encyclopedia > Apatite
Apatite

General
Category Phosphate mineral group
Chemical formula Ca5(PO4)3(F,Cl,OH)
Identification
Color Transparent to translucent, usually green, less often colorless, yellow, blue to violet, pink, brown.[1]
Crystal habit Tabular, prismatic crystals, massive, compact or granular
Crystal system Hexagonal Dipyramidal (6/m)[2]
Cleavage [0001] Indistinct, [1010] Indistinct[2]
Fracture Conchoidal to uneven[1]
Mohs Scale hardness 5[1]
Luster Vitreous[1] to subresinous
Polish luster Vitreous[1]
Refractive index 1.634 - 1.638 (+.012, -.006)[1]
Optical Properties Double refractive, uniaxial negative[1]
Birefringence .002-.008[1]
Dispersion .013[1]
Pleochroism Blue stones - strong, blue and yellow to colorless. Other colors are weak to very weak.[1]
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.[1]
Streak White
Specific gravity 3.16 - 3.22[2]
Diaphaneity Transparent to translucent[2]

Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite, and chlorapatite, named for high concentrations of OH-, F-, or Cl- ions, respectively, in the crystal. The formula of the admixture of the three most common species is written as Ca5(PO4)3(OH, F, Cl), and the formulae of the individual minerals are written as Ca5(PO4)3(OH), Ca5(PO4)3F and Ca5(PO4)3Cl, respectively. Image File history File links Download high resolution version (2240x1348, 2135 KB) Summary Two crystals, 1. ... This article or section does not cite any references or sources. ... See: transparency (optics) alpha compositing GIF#Transparency transparency (overhead projector) market transparency transparency (telecommunication) transparency (computing) For X11 pseudo-transparency, see pseudo-transparency. ... In optics, transparency is the property of being transparent, or allowing light to pass. ... In mineralogy, shape and size give rise to descriptive terms applied to the typical appearance, or habit of crystals. ... A crystal system is a category of space groups, which characterize symmetry of structures in three dimensions with translational symmetry in three directions, having a discrete class of point groups. ... In crystallography, the hexagonal crystal system is one of the 7 lattice point groups. ... Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite planes, creating smooth surfaces, of which there are several named types: Basal cleavage: cleavage parallel to the base of a crystal, or to the plane of the lateral axes. ... For fractures in geologic formations, see Rock fracture. ... Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer. ... Lustre (American English: luster) is a description of the way light interacts with the surface of a crystal, rock or mineral. ... The refractive index (or index of refraction) of a medium is a measure for how much the speed of light (or other waves such as sound waves) is reduced inside the medium. ... A calcite crystal laid upon a paper with some letters showing the double refraction Birefringence, or double refraction, is the decomposition of a ray of light into two rays (the ordinary ray and the extraordinary ray) when it passes through certain types of material, such as calcite crystals, depending on... Dispersion of a light beam in a prism. ... Pleochroism is an optical phenomenon in which grains of a rock appear to be different colors when observed at different angles,under a petrographic microscope. ... Fluorescence induced by exposure to ultraviolet light in vials containing various sized Cadmium selenide (CdSe) quantum dots. ... The streak (also called powder color) of a mineral is the color of the powder produced when it is dragged across a unweathered surface. ... Relative density (also known as specific gravity) is a measure of the density of a material. ... Wikipedia does not yet have an article with this exact name. ... Hydroxylapatite is a naturally occurring form of calcium apatite with the formula Ca5(PO4)3(OH), but is usually written Ca10(PO4)6(OH)2 to denote that the crystal unit cell comprises two molecules. ... Apatite is a group of minerals, usually referring to: hydroxylapatite, fluorapatite, and chlorapatite, named for high concentrations of OH-, F-, or Cl- ions, respectively, in the crystal lattice. ... Apatite is a group of minerals, usually referring to: hydroxylapatite, fluorapatite, and chlorapatite, named for high concentrations of OH-, F-, or Cl- ions, respectively, in the crystal lattice. ... // Hydroxyl group The term hydroxyl group is used to describe the functional group -OH when it is a substituent in an organic compound. ... General Name, Symbol, Number fluorine, F, 9 Chemical series halogens Group, Period, Block 17, 2, p Appearance Yellowish brown gas Atomic mass 18. ... General Name, Symbol, Number chlorine, Cl, 17 Chemical series halogens Group, Period, Block 17, 3, p Appearance yellowish green Standard atomic weight 35. ... An electrostatic potential map of the nitrate ion (NO3−). Areas coloured red are lower in energy than areas colored yellow An ion is an atom or group of atoms which have lost or gained one or more electrons, making them negatively or positively charged. ... Quartz crystal Synthetic bismuth hopper crystal Insulin crystals Gallium, a metal that easily forms large single crystals A huge monocrystal of potassium dihydrogen phosphate grown from solution by Saint-Gobain for the megajoule laser of CEA. In chemistry and mineralogy, a crystal is a solid in which the constituent atoms... General Name, Symbol, Number calcium, Ca, 20 Chemical series alkaline earth metals Group, Period, Block 2, 4, s Appearance silvery white Standard atomic weight 40. ... Above is a ball-and-stick model of the inorganic hydrogenphosphate anion (HPO42−). Colour coding: P (orange); O (red); H (white). ...


Apatite is one of few minerals that are produced and used by biological micro-environmental systems. Hydroxylapatite is the major component of tooth enamel. A relatively rare form of apatite in which most of the OH groups are absent and containing many carbonate and acid phosphate substitutions is a large component of bone material. Tooth enamel is the hardest and most highly mineralized substance of the body , and with dentin, cementum, and dental pulp is one of the four major parts of the tooth. ... Grays Anatomy illustration of a human femur. ...


Fluorapatite (or fluoroapatite) is more resistant to acid attack than is hydroxyapatite. For this reason, toothpaste typically contain a source of fluoride anions (e.g. sodium fluoride, sodium monofluorophosphate). Similarly, fluoridated water, allow exchange in the teeth of fluoride ions for hydroxy groups in apatite. Too much fluoride results in dental fluorosis and/or skeletal fluorosis. Apatite is a group of minerals, usually referring to: hydroxylapatite, fluorapatite, and chlorapatite, named for high concentrations of OH-, F-, or Cl- ions, respectively, in the crystal lattice. ... ... Sodium monofluorophosphate Sodium monofluorophosphate (also disodium monofluorophosphate or MFP) is a chemical with the formula Na2PO3F. Its molecular weight is 143. ... This article needs cleanup. ... A humans visible teeth. ... Picture of a mild case of fluorosis. ... Skeletal fluorosis is a bone disease exclusively caused by excessive consumption of fluoride. ...


In the United States, apatite is often used to fertilize tobacco. It partially starves the plant of nitrogen, which gives American cigarettes a different taste from those of other countries. Shredded tobacco leaf for pipe smoking Tobacco can also be pressed into plugs and sliced into flakes Tobacco is an agricultural product processed from the fresh leaves of plants in genus Nicotiana. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... Two unlit filtered cigarettes. ...


Fission tracks in apatite are commonly used to determine the thermal history of orogenic (mountain) belts and of sediments in sedimentary basins. Fission track dating is a radiometric dating technique based on analyses of the damage trails or tracks left by fission fragments in certain uranium bearing minerals and glass. ... The term sedimentary basin is used to refer to any geographical feature exhibiting subsidence and consequent infilling by sedimentation. ...


Phosphorite is the name given to impure, massive apatite.

Contents

Gemology

Apatite is infrequently used as a gemstone. Transparent stones of clean color have been faceted, and chatoyant specimens have been cabochon cut.[1] Chatoyant stones are known as cat's-eye apatite,[1] transparent green stones are known as asparagus stone,[1] and blue stones have been called moroxite.[3] Crystals of rutile may have grown in the crystal of apatite so when in the right light, the cut stone displays a cat's eye effect. Major sources for gem apatite are:[1] Brazil, Burma, and Mexico. Other sources include:[1] Canada, Czechoslovakia, Germany, India, Madagascar, Mozambique, Norway, South Africa, Spain, Sri Lanka, and the US. A selection of gemstone pebbles made by tumbling rough rock with abrasive grit, in a rotating drum. ... In gemology, chatoyancy is an optical reflectance effect seen in certain gemstones. ... A cabochon or cabouchon is a gemstone which has been shaped and polished as opposed to facetted. ... Moroxite is a mineral, a crystallized form of apatite. ... United States may refer to: Places: United States of America SS United States, the fastest ocean liner ever built. ...


See also

Apatite Crystal, Mexico
Apatite Crystal, Mexico

Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Gem animals. ... Thermal history modelling is an exercise undertaken during basin modelling to evaluate the temperature history of stratigraphic layers in a sedimentary basin. ...

References

  1. ^ a b c d e f g h i j k l m n o p Gemological Institute of America, GIA Gem Reference Guide 1995, ISBN 0-87311-019-6
  2. ^ a b c d http://webmineral.com/data/Apatite.shtml Webmineral data
  3. ^ Streeter, Edwin W., Precious Stones and Gems 6th edition, George Bell and Sons, London, 1898, p306
  • Apatite on Mineral galleries

The Gemological Institute of America, or GIA, is a non-profit institute dedicated to research and education in the field of gemology. ...

Further reading

  • Schmittner Karl-Erich and Giresse Pierre, 1999. Micro-environmental controls on biomineralization: superficial processes of apatite and calcite precipitation in Quaternary soils, Roussillon, France. Sedimentology 46/3: 463-476.

  Results from FactBites:
 
APATITE (Calcium (Fluoro-, Chloro-, Hydroxyl-) Phosphate) (338 words)
Apatite is actually three different minerals depending on the predominance of either fluorine, chlorine or the hydroxyl group.
An irony of the name apatite is that apatite is the mineral that makes up the teeth in all vertebrate animals as well as their bones.
Apatite is widely distributed in all rock types; igneous, sedimentary and metamorphic, but is usually just small disseminated grains or cryptocrystalline fragments.
Apatite - Wikipedia, the free encyclopedia (197 words)
Apatite is a group of phosphate minerals, usually referring to hydroxylapatite, fluorapatite, and chlorapatite, named for high concentrations of OH
Apatite is one of few minerals that are produced and used by biological systems.
Fission tracks in apatite are commonly used to determine the thermal history of orogenic (mountain) belts and of sediments in sedimentary basins.
  More results at FactBites »

 
 

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