Phosphate minerals and their features

Phosphate mineral, any of a group of naturally occurring inorganic salts of phosphoric acid, H3(PO4). More than 200 species of phosphate minerals are recognized, and structurally they all have isolated (PO4) tetrahedral units. 

Pyromorphite

Chemical Formula : Pb5(PO4)3Cl 

Mohs Scale :  3,5- 4

Crystal System : Hexagonal

Specific gravity : 6.5 - 7.1 

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Turquoise

Chemical Formula : CuAl6(PO4)4(OH)8·4H2O

Mohs Scale :  5 - 6

Crystal System : Triclinic

Vivianite

Chemical Formula : Fe2+3(PO4)2·8H2

Mohs Scale :  1,5-2

Crystal System : Monoclinic

Wavellite

Chemical Formula : Al3(PO4)2(OH,F)3·5H2

Mohs Scale :  3,5- 4

Crystal System : Orthorhombic

Specific gravity : 2.36

Apatite

Chemical Formula : Ca5(PO4)3(F,Cl,OH) 

Mohs Scale :  5

Crystal System : Hexagonal

Specific gravity : 3.16