Phosphate minerals

Phosphate minerals are those minerals that contain the tetrahedrally coordinated phosphate (PO₄^3-) anion along with the freely substituting arsenate (AsO₄^3-) and vanadate (VO₄^3-). Chlorine (Cl^-), fluorine (F^-), and hydroxide (OH^-) anions also fit into the crystal structure.

Additional recommended knowledge

What is the Correct Way to Check Repeatability in Balances?

Recognize and detect the effects of electrostatic charges on your balance

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The phosphate class of minerals is a large and diverse group, however, only a few species are relatively common.

Examples include:

• triphylite Li(Fe,Mn)PO₄
• monazite (Ce,La,Y,Th)PO₄
• Apatite group Ca₅(PO₄)₃(F,Cl,OH)
  • hydroxylapatite Ca₅(PO₄)₃OH
  • fluorapatite Ca₅(PO₄)₃F
  • chlorapatite Ca₅(PO₄)₃Cl
• pyromorphite Pb₅(PO₄)₃Cl
• vanadinite Pb₅(VO₄)₃Cl
• erythrite Co₃(AsO₄)₂·8H₂O
• amblygonite LiAlPO₄F
• lazulite (Mg,Fe)Al₂(PO₄)₂(OH)₂
• wavellite Al₃(PO₄)₂(OH)₃·5H₂O
• turquoise CuAl₆(PO₄)₄(OH)₈·5H₂O
• autunite Ca(UO₂)₂(PO₄)₂·10-12H₂O
• carnotite K₂(UO₂)₂(VO₄)₂·3H₂O
• phosphophyllite Zn₂(Fe,Mn)(PO₄)₂•4H₂O

Applications

Phosphate minerals are often used for control of rust and prevention of corrosion on ferrous materials, applied with electrochemical conversion coatings.

See also

• Parkerizing

References

• Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., John Wiley and Sons, New York ISBN 0-471-80580-7
• Webmineral - Strunz
• Webmineral - Dana