Constituent
Name
Whitlockite
IMA name
Whitlockite
Class
non-silicate mineral
Compound type
phosphate
Constituent abundance in material
Relevance
main - major
Arrangement
single phase
Mass fraction
1.0
Chemical composition
Formula
$Ca_9(Mg,Fe^{2+})(PO_4)_6(PO_3OH)$
Chemical formula
Ca9(Mg,Fe)(PO4)6(PO3OH)
Elemental formula
Ca9 (Mg)0-1 (Fe2+)0-1 P7 O28 H
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Ca$ Calcium element 9 constituent element main
$Mg$ Magnesium element 0 - 1 constituent element main
$Fe^{2+}$ Iron(II) cation element 0 - 1 constituent element main
$(PO_4)^{3-}$ Phosphate anion chemical function 6 anionic radical main
$P$ Phosphorus element 1 constituent element main
$O$ Oxygen element 4 constituent element main
$H$ Hydrogen element 1 constituent element main
Chemical functions
  Function Number
$(PO_4)^{3-}$ 6
Chemical bonds
  Bond Number
$\dddot - \dddot - \dddot - P \dddot - O^{-3/4}$ 4
Oxides
Formula $CaO$ $MgO$ $FeO$ $P_{2}O_{5}$ $H_{2}O$
Mass fraction (%) 47.1 2.63 3.35 46.37 0.84
Oxides comments
with a typical formula $Ca_9Mg_{0.7}Fe^{2+}_{0.5}(PO_4)_6(PO_3OH)$

Strunz

Class
phosphates - arsenates - vanadates (08)
Division
phosphates, etc. without additional anions, without H2O (08.A)
Family
with medium-sized and large cations (08.AC)
Code
08.AC.45

Dana

Major class
phosphates, arsenates, vanadates (VII)
Class
anhydrous phosphates (38)
Type
(A+ B++)3 (XO4)2 (38.03)
Group
Whitlockite group (38.03.04)
Code
38.03.04.01
Phase type
crystalline
Crystal system
trigonal
Crystal class
ditrigonal-pyramidal
Crystal class symbol
3m (C3v)
Crystal spacegroup
R3c
Texture
monocrystalline
Molar mass
1071.45 $g/mol$
Density
3.13 $g/cm^3$
Refringence type
uniaxial
Refringence sign
positive
Birefringence
0.003
Refraction index $n_{\alpha}$
1.626
Refraction index $n_{\beta}$
1.629
Color
colorless, white, gray, gray white, yellowish
Diaphaneity
transparent to translucent
Luster
vitreous