# Borate sulfate

Borate sulfates are mixed anion compounds containing separate borate and sulfate anions. They are distinct from the borosulfates where the borate is linked to a sulfate via a common oxygen atom.

## List

| | chem | mw | crystal system | space group | unit cell Å | volume | density | comment |
| sulfoborite | Mg$_3$(OH)[B(OH)$_4$]$_2$(SO$_4$)F | | orthorhombic | Pnma | a=10.132 b=12.537 c=7.775 | 987.6 | | Biaxial (-) n$_α$ = 1.527 n$_β$ = 1.536 n$_γ$ = 1.551 2V 79° Max birefringence δ = 0.024 |
| Heidornite | Na$_2$Ca$_3$B$_5$O$_8$(OH)$_2$(SO$_4$)$_2$Cl | | monoclinic | C2/c | a = 10.19, b = 7.76, c = 18.81 β = 93.33° Z=4 | 1,485 | 2.753 | Biaxial (+) n$_α$ = 1.579 n$_β$ = 1.588 n$_γ$ = 1.604 2V 63° to 77° Max birefringence δ = 0.025 |
| Charlesite | Ca$_6$Al(SO$_4$)$_2$B(OH)$_4$(O,OH)$_{12}$•26H$_2$O | | trigonal | P3$_1$c | a = 11.161, c = 21.212 | 2,288 | 1.77 | Uniaxial (-) n$_ω$ = 1.492(3) n$_ε$ = 1.475(3) Max birefringence δ = 0.017 |
| Vitimite | Ca$_6$B$_{14}$O$_{19}$(SO$_4$)(OH)$_{14}$•5H$_2$O | | monoclinic | P2/m | a = 14.10, b = 19.53, c = 14.05 β = 120.39°=4 | 3,337 | | Biaxial (-) n$_α$ = 1.532(3) n$_β$ = 1.537(1) n$_γ$ = 1.540(1) Max birefringence δ = 0.008 |
| Harkerite | Ca$_{12}$Mg$_4$Al(BO$_3$)$_3$(SiO$_4$)$_4$(CO$_3$)$_5$ · H$_2$O | | trigonal | R3m | a = 18.131 Å α = 33.46° | 1,614 | | Uniaxial n$_α$ = 1.649 - 1.653 n$_β$ = 1.649 - 1.653 |
| Tatarinovite | Ca$_3$Al(SO$_4$)[B(OH)$_4$](OH)$_6$ · 12H$_2$O | | Hexagonal | P6$_3$ | a = 11.1110, c = 10.6294 | 1,136 | 1.79 | colourless Uniaxial (+) n$_ω$ = 1.475 n$_ε$ = 1.496 Max birefringence δ = 0.021 |
| Sturmanite | Ca$_6$Fe$^{3+}$2(SO$_4$)$_{2.5}$[B(OH)$_4$](OH)$_{12}$•25H$_2$O | | trigonal | P3$_1$c | a = 11.16, c = 21.79 Z=2 | 2,350 | | yellow Uniaxial (+/-) n$_ω$ = 1.499 - 1.500 n$_ε$ = 1.497 - 1.505 Max birefringence δ = 0.002 |
| | [Ni(atta)(SO$_4$)$_{0.5}$]·[B$_5$O$_6$(OH)$_4$] | 514.13 | monoclinic | P2$_1$/c | a=9.0512 b=15.2776 c =15.0142, β=90.325° Z=4 | 2076.14 | 1.645 | |
| Buryatite | Ca$_3$(Si,Fe,Al)(SO$_4$)[B(OH)$_4$]O(OH)$_5$ · 12H$_2$O | | trigonal | P3$_1$c | a = 11.14, c = 20.99 Z=4 | 2,256 | 1.89 | Uniaxial (-) n$_ω$ = 1.523(3) n$_ε$ = 1.532(3) Max birefringence δ = 0.009 |
| | Rb$_3$H(SO$_4$)$_2$(B$_2$O$_3$)$_2$ | | hexagonal | P6$_3$/m | a = 6.502, c = 19.02 Z=2 | | 2.803 | |
| Fontarnauite | Na$_2$Sr(SO$_4$)B$_5$O$_8$(OH)•2H$_2$O | | monoclinic | P2$_1$/c | a=6.458 b=22.299 c=8.571 β=103.05 Z=4 | 1,203 | | |
| | Y(SO$_4$)[B(OH)$_4$](H$_2$O)·H$_2$O | | triclinic | P1 | a=5.9679 b=6.8559 c=10.1698 α=79.608 β=76.673 γ=89.220 Z=2 | 398.02 | 2.502 | |
| | Cs$_3$H(SO$_4$)$_2$(B$_2$O$_3$)$_2$ | | hexagonal | P6$_3$/m | a = 6.5648, c = 19.5669 Z = 2 | | 3.322 | |
| | La(SO$_4$)[B(OH)$_4$](H$_2$O) | 331.83 | triclinic | P1 | a=6.2808 b=6.8321 c=8.6830 α=82.475 β=76.758 γ=87.300 Z=2 | 359.51 | 3.065 | |
| | Pr(SO$_4$)[B(OH)$_4$](H$_2$O)$_2$ | 351.84 | monoclinic | P2$_1$/m | a=6.2359 b=9.5542 c=6.8236 β=93.852 Z=2 | 405.64 | 2.881 | |
| | Nd(SO$_4$)[B(OH)$_4$](H$_2$O)$_2$ | 355.17 | monoclinic | P2$_1$/m | a=6.2119 b=9.5328 c=6.7923 β=93.755 Z=2 | 401.35 | 2.939 | |
| | Sm(SO$_4$)[B(OH)$_4$](H$_2$O) | 343.27 | triclinic | P1 | a=6.1467 b=6.7280 c=8.6068 α=81.769 β=76.653 γ=87.259 Z=2 | 342.71 | 3.326 | |
| | Sm(SO$_4$)[B(OH)$_4$](H$_2$O)$_2$ | 361.30 | monoclinic | P2$_1$/m | a=6.1601 b=9.5416 c=6.7589 β=93.816 Z=2 | 396.39 | 3.027 | |
| | Eu(SO$_4$)[B(OH)$_4$](H$_2$O) | 344.88 | triclinic | P1 | a=6.1205 b=6.7090 c=8.5844 α=81.713 β=76.680 γ=87.294 Z=2 | 339.40 | 3.375 | |
| | Eu(SO$_4$)[B(OH)$_4$](H$_2$O)$_2$ | 362.89 | monoclinic | P2$_1$/m | a=6.1322 b=9.5139 c=6.7343 β=93.683 Z=2 | 392.08 | 3.074 | |
| | Gd(SO$_4$)[B(OH)$_4$](H$_2$O)$_2$ | 368.19 | monoclinic | P2$_1$/m | a=6.1148 b=9.5078 c=6.7164 β=93.611 Z=2 | 389.70 | 3.138 | |
| | Tb(SO$_4$)[B(OH)$_4$](H$_2$O)·H$_2$O | 369.87 | triclinic | P1 | a=6.0139 b=6.8972 c=10.1753 α=79.616 β=76.590 γ=89.106 Z=2 | 403.42 | 3.045 | |
| | Dy(SO$_4$)[B(OH)$_4$](H$_2$O)·H$_2$O | 373.43 | triclinic | P1 | a=5.9880 b=6.8728 c=10.1638 α=79.652 β=76.597 γ=89.153 Z=2 | 400.12 | 3.100 | |
| | Ho(SO$_4$)[B(OH)$_4$](H$_2$O)·H$_2$O | 375.86 | triclinic | P1 | a=5.9701 b=6.8570 c=10.1580 α=79.588 β=76.636 γ=89.193 Z=2 | 397.75 | 3.138 | |
| | Er(SO$_4$)[B(OH)$_4$](H$_2$O)·H$_2$O | 378.19 | triclinic | P1 | a=5.9529 b=6.8401 c=10.1553 α=79.598 β=76.642 γ=89.198 Z=2 | 395.54 | 3.175 | |
| | Tm(SO$_4$)[B(OH)$_4$](H$_2$O)·H$_2$O | 379.86 | triclinic | P1 | a=5.9289 b=6.8232 c=10.1422 α=79.531 β=76.663 γ=89.263 Z=2 | 392.40 | 3.215 | |
| | Yb(SO$_4$)[B(OH)$_4$](H$_2$O)·H$_2$O | 383.97 | triclinic | P1 | a=5.9150 b=6.8090 c=10.1454 α=79.541 β=76.669 γ=89.243 Z=2 | 390.82 | 3.263 | |
| | Lu(SO$_4$)[B(OH)$_4$](H$_2$O)·H$_2$O | 385.91 | triclinic | P1 | a=5.8992 b=6.7954 c=10.1322 α=79.551 β=76.691 γ=89.266 Z=2 | 388.53 | 3.299 | |
| | Pb$_2$[(BO$_2$)(OH)](SO$_4$) | 570.26 | monoclinic | P2$_1$/m | a=6.982 b=5.3917 c=8.167 β=98.643° | 303.9 | 6.231 | decompose 335 °C; band gap 4.08 |
| | Pb$_4$(BO$_3$)$_2$(SO$_4$) | 1042.44 | monoclinic | P2$_1$/c | a=6.9363 b=15.8784 c=9.6053 β=110.770° Z=4 | 989.15 | 7.000 | melt 689 °C; band gap 4.03 eV |