2M+ REVIEWS | 1000+ NEW GEMS DAILY |

Niste licitirali na ovoj dražbi.

$21.00
Trenutna ponuda
0
Ponude
Zatvoreno
23/01/2022 09:50 am
0
145
1

Apatite, 1.475ct, pretty colour, medium clairity

SKU
Dimenzije (mm)
8.920 x 6.700 x 4.100mm
Težina (cts)
1.475
Clarity
SI
Treatment
No Treatment
Tip
Faceted
Boje

Apatite is a group of phosphate minerals, usually referring to hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH, F and Clions, 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, 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 απατείν (apatein), which means to deceive or to be misleading.

Apatite is found in sedimentary, metamorphic, igneous, and volcanic rocks. Apatite can form in sedimentary processes, igneous processes (e.g., Pegmatite), metamorphic processes, and in hydrothermal vents, as well as production by biological systems.

Apatite is one of a few minerals produced and used by biological micro-environmental systems. Apatite is the defining mineral for 5 on the Mohs scale. Hydroxyapatite, also known as hydroxylapatite, is the major component of tooth enamel and bone mineral. 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.

Fluorapatite (or fluoroapatite) is more resistant to acid attack than is hydroxyapatite; in the mid-20th century, it was discovered that communities whose water supply naturally contained fluorine had lower rates of dental caries. Fluoridated water allows exchange in the teeth of fluoride ions for hydroxyl groups in apatite. Similarly, toothpaste typically contains a source of fluoride anions (e.g. sodium fluoride, sodium monofluorophosphate). Too much fluoride results in dental fluorosis and/or skeletal fluorosis.

Fission tracks in apatite are commonly used to determine the thermal histories of orogenic belts and of sediments in sedimentary basins.[7](U-Th)/He dating of apatite is also well established from noble gas diffusion studies[8][9][10][11][12][13][14] for use in determining thermal histories[15][16] and other, less typical applications such as paleo-wildfire dating.

Phosphorite is a phosphate-rich sedimentary rock, that contains between 18% and 40% P2O5. The apatite in phosphorite is present as cryptocrystalline masses referred to as collophane.

The primary use of apatite is in the manufacture of fertilizer – it is a source of phosphorus. It is occasionally used as a gemstone. Green and blue varieties, in finely divided form, are pigments with excellent covering power.

During digestion of apatite with sulfuric acid to make phosphoric acid, hydrogen fluoride is produced as a byproduct from any fluorapatite content. This byproduct is a minor industrial source of hydrofluoric acid.

Fluoro-chloro apatite forms the basis of the now obsolete Halophosphor fluorescent tube phosphor system. Dopant elements of manganese and antimony, at less than one mole-percent — in place of the calcium and phosphorus impart the fluorescence — and adjustment of the fluorine-to-chlorine ratio alter the shade of white produced. This system has been almost entirely replaced by the Tri-Phosphor system.

In the United States, apatite-derived fertilizers are used to supplement the nutrition of many agricultural crops by providing a valuable source of phosphate.

Apatites are also a proposed host material for storage of nuclear waste, along with other phosphates.

Apatite is infrequently used as a gemstone. Transparent stones of clean color have been faceted, and chatoyant specimens have been cabochon-cut.[2] Chatoyant stones are known as cat's-eye apatite, transparent green stones are known as asparagus stone, and blue stones have been called moroxite. If crystals of rutile have grown in the crystal of apatite, in the right light the cut stone displays a cat's-eye effect. Major sources for gem apatite are Brazil, Myanmar, and Mexico. Other sources include Canada, Czech Republic, Germany, India, Madagascar, Mozambique, Norway, South Africa, Spain, Sri Lanka, and the United States.

Apatite is occasionally found to contain significant amounts of rare-earth elements and can be used as an ore for those metals. This is preferable to traditional rare-earth ores such as monazite, as apatite is not very radioactive and does not pose an environmental hazard in mine tailings. However, apatite often contains uranium and its equally radioactive decay-chain nuclides.

The standard enthalpies of formation in the crystalline state of hydroxyapatite, chlorapatite and a preliminary value for bromapatite, have been determined by reaction-solution calorimetry. Speculations on the existence of a possible fifth member of the calcium apatites family, iodoapatite, have been drawn from energetic considerations.

Structural and thermodynamic properties of crystal hexagonal calcium apatites, Ca10(PO4)6(X)2 (X= OH, F, Cl, Br), have been investigated using an all-atom Born-Huggins-Mayer potential by a molecular dynamics technique. The accuracy of the model at room temperature and atmospheric pressure was checked against crystal structural data, with maximum deviations of c. 4% for the haloapatites and 8% for hydroxyapatite. High-pressure simulation runs, in the range 0.5-75 kbar, were performed in order to estimate the isothermal compressibility coefficient of those compounds. The deformation of the compressed solids is always elastically anisotropic, with BrAp exhibiting a markedly different behavior from those displayed by HOAp and ClAp. High-pressure p-V data were fitted to the Parsafar-Mason equation of state with an accuracy better than 1%.

The monoclinic solid phases Ca10(PO4)6(X)2 (X= OH, Cl) and the molten hydroxyapatite compound have also been studied by molecular dynamics.

 

Shipping: For special requests such as express delivery please contact me. For lost stones the seller is not liable, therefore an additional insurance is recommended. Right of return within two weeks after receiving the shipment. Payment via PayPal, Credit Card, or Bank transfer is possible. For the shipping I generally use: Austrian Post or FedEx. Unfortunately from Austria only DHL "express" is possible.

Please pay your stones in between five days or contact me. Otherwise I need to cancel the deal.

If there is anything you shouldn't be satisfied with please just let me now and we will find a way to solve every problem. My aim is to make you happy with beautiful stones of good quality, good communication is the easiest way to find a solution!


Pružatelj usluge dostave Dostava u Austria Dostava u ostatak svijeta
Standard Shipping - Tracked $8.00 / :dani dani $15.00 / :dani dani
:zemlja
Standard Shipping - Tracked je snižen na $15.00 na narudžbe s 3 ili više artikala
Ostatak svijeta
Standard Shipping - Tracked je snižen na $17.00 na narudžbe s 3 ili više artikala
FedEx $27.00 / :dani dani $46.00 / :dani dani
:zemlja
FedEx je snižen na $26.00 na narudžbe s 2 ili više artikala
Ostatak svijeta
FedEx je snižen na $45.00 na narudžbe s 2 ili više artikala
Express Shipping $36.00 / :dani dani $75.00 / :dani dani
:zemlja
Express Shipping je snižen na $40.00 na narudžbe s 3 ili više artikala
Ostatak svijeta
Express Shipping je snižen na $65.00 na narudžbe s 3 ili više artikala
Registered Shipping $9.00 / :dani dani $16.00 / :dani dani
:zemlja
Registered Shipping je snižen na $15.00 na narudžbe s 3 ili više artikala
Ostatak svijeta
Registered Shipping je snižen na $15.00 na narudžbe s 3 ili više artikala
Standard Shipping - Untracked $5.00 / :dani dani $13.00 / :dani dani
:zemlja
Standard Shipping - Untracked je snižen na $15.00 na narudžbe s 3 ili više artikala
Ostatak svijeta
Standard Shipping - Untracked je snižen na $13.00 na narudžbe s 3 ili više artikala

stonehengejpd
stonehengejpd
Selling all kind of gems, great quality at affordable prices, based in the heart of Europe! In case you may have special wishes just let me know :-) If you shouldn´t be satisfied with an order please do not give a negative feedback just let me know and there is always a way to find a solution that everybody is happy!
:Grad drzava
Provjereno
:ukupne povratne informacije

  • mattosh666
    mattosh666
    Pozitivan

    Thank you! So beautiful. Starting following you. Definitely doing more business

  • kathmedrn
    kathmedrn
    Pozitivan

    Such a beautiful stone! Prettier than the pic!

Povijest ponuda (0)
Još nema ponuda.

Zašto korisnici nadmašuju same sebe?

Kada se postavi ponuda, to je maksimalni iznos koji je korisnik spreman ponuditi za proizvod. Naš sustav će zatim automatski licitirati u ime tog korisnika, postupno povećavajući licitaciju kako bi zadržao svoju poziciju ponuditelja najviše, do navedenog maksimuma.

Kada postoji ikona koja označava "Automatsku ponudu", to znači da naš sustav aktivno daje ponude za korisnika na temelju njihove maksimalne ponude. Ovo se može činiti kao da korisnici sami sebe nadmašuju, ali to je jednostavno rezultat ažuriranja ponude sustava kako bi odražavala maksimalno ograničenje korisnika.

Revizija

Program Gemstone Sheriff omogućuje našim članovima da zatraže reviziju bilo kojeg proizvoda, koju dovršava neovisna :kvalifikacija koja procjenjuje točnost opisa artikla i slika.

Detalji dostave

dostava:
$15.00 21 days putem Standard Shipping - Tracked
Brodovi iz:
Austria

Načini plačanja

  • paypal
  • stripe
  • escrow
  • gempay
Ovaj prodavač dodaje 20.00% porez na transakcije u Austria.

Pregled

Vrsta unosa : Standard
Identifikacijski broj proizvoda : 1670099
Početna ponuda : $21
Počinje : 29th November 2021 03:50 am AEST
Završava : 24th January 2022 03:50 am AEST
* Sve cijene su u :valuti