Constituent
- Name
- Apatite
- IMA name
- Apatite
- Class
- non-silicate mineral
- Compound type
- phosphate
- Comments
- There are 3 endmembers: Apatite-(CaF) [$Ca_5(PO_4)_3F$], Apatite-(CaCl) [$Ca_5(PO_4)_3Cl$] and Apatite-(CaOH) [$Ca_5(PO_4)_3(OH)$]
- Relevance
- main - major
- Arrangement
- single phase
- Mass fraction
- 1.0
- Formula
- $(Ca_5)(PO_4)_3(OH,F,Cl)$
- Chemical formula
- Ca5(PO4)3(OH,F,Cl)
- Elemental formula
- Ca5 P3 (O)12-13 (H)0-1 (F)0-1 (Cl)0-1
- Isotope mixture type
- terrestrial abundance
- Oxides
-
Formula $CaO$ $P_{2}O_{5}$ $H_{2}O$ $F$ $Cl$ Mass fraction (%) 55.07 34.28 0.59 1.24 2.32 - Oxides comments
- values for x=y=0.33, $Cl_2O$=-0.52%, $F_2O$=-0.52%
Strunz
- Class
- phosphates - arsenates - vanadates (08)
- Division
- phosphates, etc. with additional anions, without H2O (08.B)
- Family
- with only large cations, (OH, etc.):RO4 = 0.33:1 (08.BN)
- Code
- 08.BN.05
Dana
- Major class
- phosphates, arsenates, vanadates (VII)
- Class
- anhydrous phosphates containing hydroxyl or halogen (41)
- Type
- where (A)5 (XO4)3 Zq (41.08)
- Group
- Apatite group (41.08.01)
- Code
- 41.08.01.00
- Phase type
- crystalline
- Crystal system
- hexagonal
- Crystal class
- dipyramidal
- Crystal class symbol
- 6/m (C6h)
- Crystal spacegroup
- P6(3)/m
- Texture
- monocrystalline
- Molar mass
- 502.31 - 520.76 $g/mol$
- Density
- 3.08 - 3.2 $g/cm^3$
- Refringence type
- uniaxial
- Refringence sign
- negative
- Birefringence
- 0.0025 - 0.0075
- Refraction index $n_{\alpha}$
- 1.630 - 1.675
- Refraction index $n_{\beta}$
- 1.6325 - 1.6675
- Color
- colorless, white, gray, yellow, yellowish green
- Diaphaneity
- transparent to opaque
- Luster
- vitreous