Fluoride phosphate
The fluoride phosphates or phosphate fluorides are inorganic double salts that contain both fluoride and phosphate anions. In mineralogy, Hey's Chemical Index of Minerals groups these as 22.1. The Nickel-Strunz grouping is 8.BN.
Related mixed anion compounds are the chloride phosphates, the fluoride arsenates and fluoride vanadates.
Minerals
| name | formula | ratio PO4:F | formula weight | crystal system | space group | unit cell | volume | density | refractive index | comment | reference |
| Althausite | Mg42 | 2:~1 | Orthorhombic | Pnma | a = 8.258 b = 6.054, c = 14.383 | 719.06 | 2.97 | Biaxial nα = 1.588 nβ = 1.592 nγ = 1.598 2V: measured: 70°, calculated: 80° Max birefringence: δ = 0.010 | |||
| Amblygonite | LiAlF | 1:1 | Triclinic | P | a = 6.644 b = 7.744 c = 6.91 α = 90.35°, β = 117.33°, γ = 91.01° Z=4 | 315.75 | 3.04-3.11 | Biaxial nα = 1.577 - 1.591 nβ = 1.592 - 1.605 nγ = 1.596 - 1.613 2V: Measured: 107° to 129.5° Birefringence: 0.020 | |||
| aravaite | Ba2Ca1863F3O | 3:3 | trigonal | R'm | a = 7.1255, c = 66.290 Z=3 | 2914.8 | |||||
| Arctite | Na2Ca43F | 3:1 | Trigonal | R'm | a = 7.078 c = 41.203 Z=6 | 1,787.64 | 3.13 | Uniaxial nω = 1.578 nε = 1.577 Birefringence: 0.001 | |||
| Ariegilatite | BaCa1242F2O | Trigonal | Rm | a = 7.1551 c = 41.303 | 1381.2 | Uniaxial nω = 1.650 nε = 1.647 Max Birefringence: δ = 0.003 | |||||
| Babefphite | BaBePO4 | 1:~1 | Tetragonal | Uniaxial nω = 1.629 nε = 1.632 Max birefringence: δ = 0.003 | |||||||
| Belovite- | NaCeSr33F | 3:1 | Trigonal | P | a = 9.692 c = 7.201 | 585.80 | 4.19 | Uniaxial nω = 1.653 - 1.660 nε = 1.634 - 1.640 Birefringence: 0.015 | |||
| Belovite- | NaLaSr33F | 3:1 | Trigonal | P | a = 9.647 c = 7.17 | 577.88 | 4.19 | Uniaxial nω = 1.653 nε = 1.635 - 1.636 Max birefringence: δ = 0.018 | |||
| Bøggildite | Na2Sr2Al2PO4F9 | 1:9 | Monoclinic | Biaxial nα = 1.462 nβ = 1.466 nγ = 1.469 2V: 80° Max birefringence:δ = 0.007 | |||||||
| Carlgieseckeite- | NaNdCa33F | Trigonal | P | a = 9.4553 c = 6.9825 | 540.62 | 3.91 | |||||
| Cloncurryite | Cu0.50.5Al22F2 · 5H2O | 2:2 | Monoclinic | P21/b | a = 4.9573 b = 12.1824 c = 18.9749 β = 90.933° Z=4 | 1145.78 | 2.525 | Biaxial nα = 1.548 nγ = 1.550 2V: calculated: 56° Max brefringence: δ = 0.002 | |||
| Deloneite | Sr1.53F0.50.5 | Trigonal | P3 | a = 9.51 c = 7.01 Z=2 | 549.05 | 3.92 | Uniaxial nω = 1.682 nε = 1.660 Max birefringence: δ = 0.022 | ||||
| Fluellite | Al2F2 · 7H2O | Orthorhombic | Fddd | a = 11.22 b = 21.15 c = 8.54 | 2,027 | 2.139 - 2.17 | Biaxial nα = 1.473 - 1.490 nβ = 1.490 - 1.496 nγ = 1.506 - 1.511 Max birefringence: δ = 0.033 | ||||
| Fluorapatite | Ca53F | 3:1 | Hexagonal | P63/m | a = 9.3973 c = 6.8782 | 526.03 | 3.1-3.25 | Uniaxial nω = 1.631 - 1.650 nε = 1.627 - 1.646 Birefringence: 0.004 | |||
| Fluorcaphite | SrCaCa33F | 3:1 | Hexagonal | P63/m | a = 9.485 c = 7.000 Z=2 | 545.39 | Uniaxial nω = 1.649 nε = 1.637 Max birefringence: δ = 0.012 | ||||
| Fluorphosphohedyphane | Ca2Pb33F | 3:1 | Hexagonal | P63/m | a = 9.640, c = 7.012 Z=2 | 564.4 | 5.445 | Uniaxial nω = 1.836 nε = 1.824 Max birefringence: δ = 0.012 | |||
| Fluorstrophite | SrCaSr33F | 3:1 | Hexagonal | P63/m | a = 9.565 c = 7.115 Z=2 | 563.74 | Uniaxial nω = 1.651 nε = 1.637 Max birefringence: δ = 0.014 | ||||
| Francolite | |||||||||||
| Herderite | CaBeF | Monoclinic | a = 4.81, b = 7.7 c = 9.82 β = 90.1° | 363.7 | 3.02 | Biaxial nα = 1.556 - 1.592 nβ = 1.578 - 1.610 nγ = 1.589 - 1.620 2V: calculated: 70° Max birefringence: δ = 0.033 | |||||
| Iangreyite | Ca2Al72215 · 8H2O | 4:~15 | Trigonal | P3 2 1 | a = 6.988 c = 16.707 | 706.5 | |||||
| Isokite | CaMgF | Monoclinic | B2/b | a = 6.52 b = 8.75 c = 7.51 β = 121.47° | 365.4 | 3.15-3.27 | Biaxial nα = 1.590 nβ = 1.595 nγ = 1.615 2V:,easured: 51° Max birefringence: δ = 0.025 | ||||
| Kingite | Al32F2 · 7H2O | 2:2 | Triclinic | a = 9.15 b = 10 c = 7.24 α = 98.6°, β = 93.6°, γ = 93.2° | Biaxial | ||||||
| Kuannersuite- | NaCeBa33F0.5Cl0.5 | 6:1 | Trigonal | P | a = 9.909 c = 7.402 | 629.42 | 4.51 | ||||
| Lacroixite | NaAlF | 1:1 | Monoclinic | B2/b | a = 6.414 b = 8.207 c = 6.885 β = 115.47° | 327.20 | 3.126 - 3.29 | Biaxial nα = 1.546 nβ = 1.563 nγ = 1.580 2V: measured: 89° Birefringence: 0.034 | |||
| Magniotriplite | 2PO4F | 1:1 | Monoclinic | a = 11.92 b = 12.27 c = 9.66 β = 107.18° | 1349.8 | Biaxial nα = 1.641 nβ = 1.649 nγ = 1.661 2V: measured: 60°, calculated: 80° Max birefringence: δ = 0.020 | |||||
| Mcauslanite | Fe3Al23F · 18H2O | 4:1 | Triclinic | a = 10.05 b = 11.56 c = 6.88 α = 105.84°, β = 93.66°, γ = 106.47° | 728.7 | Biaxial nα = 1.522 nβ = 1.531 nγ = 1.534 2V: measured: 55° to 59.7°, calculated: 58° Max birefringence:δ = 0.012 | |||||
| Minyulite | KAl22 · 4H2O | 2:~1 | Orthorhombic | Pba2 | a = 9.34 b = 9.74 c = 5.52 | 502 | 2.47 | Biaxial nα = 1.531 nβ = 1.534 nγ = 1.538 2V: measured: 70°, calculated: 82° Max birefringence: δ = 0.007 | |||
| Miyahisaite | 2Ba33F | 3:1 | Hexagonal | P63/m | a = 9.921, c = 7.469 Z=2 | 636.7 | 4.511 | ||||
| Morinite | NaCa2Al22F4 · 2H2O | 2:4 | Monoclinic | 2.94 | Biaxial nα = 1.551 nβ = 1.563 nγ = 1.565 2V: measured: 43°, calculated: 44° Max birefringence: δ = 0.014 | ||||||
| Nacaphite | Na2CaF | Monoclinic | P21/b | a = 13.318 b = 7.0964 c = 10.6490 β = 113.526° Z=8 | 922.81 | Biaxial nα = 1.508 nβ = 1.515 nγ = 1.520 2V: 80° Max birefringence: δ = 0.012 | |||||
| natrophosphate | Na72F.19H2O | 2:1 | Isometric | Fd3c | a = 27.79 Z=56 | 21,461.78 | 1,71-1.72 | Isotropic | |||
| Nefedovite | Na5Ca44F | 4:1 | Triclinic | a = 5.4 Å, b = 11.64 Å, c = 16.48 Å α = 134.99°, β = 90.04°, γ = 89.96° | 732.60 | Biaxial nα = 1.571 nγ = 1.590 Max birefringence: δ = 0.019 | |||||
| Nevadaite | 6Al88F82 · 22H2O | 8:8 | Orthorhombic | P21mn | a = 12.123 b = 18.999 c = 4.961 | 2.54 | Biaxial nα = 1.540 nβ = 1.548 nγ = 1.553 2V: measured: 76°, calculated: 76° Max birefringence: δ = 0.013 | ||||
| Panasqueiraite | CaMg | 1:~1 | monoclinic | a = 6.53 b = 8.75 c = 6.91 β = 112.33° | 365.2 | 3.27 | Biaxial nα = 1.590 nβ = 1.596 nγ = 1.616 2V: measured: 51°, calculated: 58° Max birefringence: δ = 0.026 | ||||
| Richellite | CaFe3+222 | 2:~2 | a = 5.18 c = 12.61 | ||||||||
| Stronadelphite | Sr53F | 3:1 | Hexagonal | P63/m | a = 9.845 c = 7.383 | 619.72 | Uniaxial nω = 1.630 nε = 1.623 Max birefringence: δ = 0.007 | ||||
| Triplite | Mn2+2F | 1:1 | Monoclinic | P21/b | a = 11.9 b = 6.52 c = 10.09 β = 105.62° | 758.4 | 3.9 | Biaxial nα = 1.650 nβ = 1.660 nγ = 1.680 2V: measured: 70° to 90°, calculated: 72° Max birefringence: δ = 0.030 | |||
| Väyrynenite | Mn2+Be | 1:~1 | Monoclinic | P21/b | a = 5.411 b = 14.49 c = 4.73 β = 102.75° | 361.71 | 3.22 | Biaxial nα = 1.638 - 1.640 nβ = 1.658 - 1.662 nγ = 1.664 - 1.667 2V: measured: 46° to 55°, Ccalculated: 51° to 57° Max birefringence: δ = 0.026 - 0.027 | |||
| Viitaniemiite | NaAl3 | 1:~3 | Monoclinic | a = 6.83 b = 7.14 c = 5.44 β = 109.37° | 250.27 | Biaxial nα = 1.557 nβ = 1.565 nγ = 1.571 2V: measured: 81°, calculated: 80° Max birefringence: δ = 0.014 | |||||
| Wagnerite | 2F | 1:1 | Monoclinic | P21/b | a = 9.645 b = 31.659 c = 11.914 β = 108.26° | 3454.8 | 3.15 | Biaxial nα = 1.568 nβ = 1.572 nγ = 1.582 2V: Measured: 25° to 35° ? Birefringence:0.046 Max birefringence: δ = 0.015 | |||
| Wavellite | Al323 · 5H2O | 2:~3 | Orthorhombic | a = 9.621 b = 17.363 c = 6.994 | 1168.3 | 2.36 | Biaxial nα = 1.518 - 1.535 nβ = 1.524 - 1.543 nγ = 1.544 - 1.561 2V: measured: 60° to 72°, calculated: 60° to 70° Max birefringence: δ = 0.026 | ||||
| Zwieselite | Fe2+2F | 1:1 | Monoclinic | P21/b | 753.82 | Biaxial nα = 1.686 - 1.696 nβ = 1.690 - 1.704 nγ = 1.703 - 1.713 2V: measured: 58°, calculated: 60° Max birefringence: δ = 0.017 | |||||
| Na5-4.5PO4 | 1:~1 |