Borate fluoride

The borate fluorides or fluoroborates are compounds containing borate or complex borate ions along with fluoride ions that form salts with cations such as metals. They are in the broader category of mixed anion compounds. They are not to be confused with tetrafluoroborates (BF₄) or the fluorooxoborates which have fluorine bonded to boron.

Examples

formula	name	mw	system	space group	unit cell Å	volume Å3	density	comment	references
Be2(BO3)(OH,F) · H2O	Berborite		trigonal	P3	a = 4.434, c = 5.334	90.82		colourless Uniaxial (-) nω = 1.580 nε = 1.485 Max birefringence δ = 0.095	[1]
γ-Be2BO3F	γ-BBF	95.83	trigonal	R32	a=4.4418 c=19.909 Z=3	340.17	1.946	Uniaxial (-) SHG 2.3 × KDP
NH4Be2BO3F2	ABBF	132.87	trigonal	R32	a=4.4398 c=12.4697 Z=3	212.87	2.243	Uniaxial (-) no=1.49389 ne=1.41919 at 636 nm	[2]
NaBe2BO3F2	sodium beryllium borate fluoride (NBBF)			C2	a=12.643 b=8.729 c=7.591 β=113.6°	768		double layers of borate rings sandwiching barium atoms. Between pairs of double layers are sodium ions with fluoride.	[3]
Mg2(BO3)(F,OH)	Pertsevite-(F)		orthorhombic	Pna21	a = 20.49, b = 4.571, c = 11.89 Z=16	1,113.6		Density 3.12 transparent Biaxial (+) nα = 1.609 nβ = 1.620 nγ = 1.642 2V: 65° Max birefringence: δ = 0.033	[4]
Mg3(BO3)(F,OH)3	Fluoborite		hexagonal		a = 8.8, c = 3.1	208		colourless Uniaxial (-) nω = 1.570 nε = 1.534 Max birefringence δ = 0.036	[5]
Mg3(OH)[B(OH)4]2(SO4)F	sulfoborite		orthorhombic	Pnma	a=10.132 b=12.537 c=7.775	987.6		Biaxial (-) nα = 1.527 nβ = 1.536 nγ = 1.551 2V 79° Max birefringence δ = 0.024	[6]
Na6Mg3B10O18F6			monoclinic	P21/c	a=13.420 b=6.400 c=10.701 β=90.693°			band gap 5.40 eV; birefringence Δn = 0.039 at 1064 nm	[7]
NaMgBe2(BO3)2F	NMBBF			P3c1	a=4.5408 c=13.439			birefringence 0.081 at 546.1 nm	[8]
Al6(BO3)5F3	Jeremejevite		hexagonal	P63/m	a = 8.5591, c = 8.1814	519		density 3.28 Uniaxial (-) nω = 1.653 nε = 1.640 Max birefringence δ = 0.013	[9][10]
Al8(BO3)4(B2O5)F8		704.7	tetragonal	P42/mmc	a=9.134 c=19.112 Z=4	1,595		density 2.935 colourless	[9]
Na(Mg3)Al6(Si6O18)(BO3)3(OH)3F	Fluor-dravite		trigonal	R3m	a = 15.955, c = 7.153 Z=3	1,577		density 3.120 dark brown Uniaxial (-) nω = 1.645(2) nε = 1.621(2) Max birefringence δ = 0.024	[11]
Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3F	Fluor-elbaite		trigonal	R3m	a = 15.8933, c = 7.1222	1,558		blue green Uniaxial (-)	[12]
K6B12O19F4		744.32	orthorhombic	Pnma	a =15.291 b =7.707 c =8.672 Z=2	1022.0	2.419		[13]
KBe2BO3F2	KBBF		hexagonal	R32	a=4.427 c=18.744	318.3	2.40	Be2BO6F2 rings SHG 1.2 × KDP; UV cutoff 147 nm	[14]
Ca5(BO3)3F									[15]
Li3CaB2O5F		363.04	orthorhombic	Pnma	a=25.685 b=3.4697 c=5.4404 Z=2	484.84	2.487	colourless	[16]
Li5Ca9(BO3)7F2				P1
NaCaBe2B2O6F									[17]
KCaBe2B2O6F		467.64		P3_1c	a=4.705 c=14.554 Z=2	279.1	2.783		[18]
Ca(Li2Al)Al6(Si6O18)(BO3)3(OH)3F	Fluor-liddicoatite		trigonal	R3m	a = 15.875, c = 7.126 Z=3	1,555		density 3.02 Uniaxial (-) nω = 1.637 nε = 1.621 Max birefringence δ = 0.016	[19]
CaMg3(Al5Mg)(Si6O18)(BO3)3(OH)3F	Fluor-uvite		trigonal	R3m	a = 15.954, c = 7.214 Z=3	1,590		black Uniaxial nω = 1.637 - 1.668 nε = 1.619 - 1.639 Max birefringence δ = 0.018 - 0.029	[20]
KCaBe2B2O6F
Sc2F2(B2O5)		229.54	orthorhombic	Pbam	a=9.667 b=14.199 c=4.0395 Z=4	554.4	2.750	colourless	[21]
K11Sc5(B5O10)4F6			orthorhombic	Fdd2	a 56.769 b 12.207 c 12.6088			transparent to <190 nm	[22]
Na(Mn2+)3Al6(Si6O18)(BO3)3(OH)3F	Fluor-tsilaisite		trigonal	R3m	a = 15.9398, c = 7.1363	1,570		greenish yellow Uniaxial (-)	[23]
NaFe3Al6Si6B3O30F									[9]
Na(Fe2+3)Al6(Si6O18)(BO3)3(OH)3F	Fluor-schorl		trigonal	R3m	a = 16.005, c = 7.176 Z=3	1,591.9		black Uniaxial (-) nω = 1.660 - 1.661 nε = 1.636 - 1.637 Max birefringence δ = 0.024	[24]
Na(Fe3+3)Al6(Si6O18)(BO3)3O3F	Fluor-buergerite		trigonal	R3m	a = 15.8692, c = 7.1882	1,568		density 3.311 brown Uniaxial (-) nω = 1.735 nε = 1.655 Birefringence 0.080	[25]
Ca(Fe2+)3MgAl5(Si6O18)(BO3)3(OH)3F	Fluor-feruvite								[26]
KCaZn2(BO3)2F
Li6RbB2O6F		263.73	orthorhombic	Pnma	a=8.41 b=15.96 c=5.08 Z=2	682	2.568		[27]
RbBe2BO3F2	RBBF		Trigonal	R32	a=4.434 c=19.758 z=3			also contains BeO3F tetrahedra and BO3. It transmits radiation from 180 to 3500 nm.	[28]
Rb18Mg6(B5O10)3(B7O14)2F			monoclinic	C2/c	a=11.06 b=19.70 c=31.01 β=90.13°				[29]
RbCaBe2B2O6F			Trigonal	R32					[30]
KSrBe2B2O6F									[17]
LiSr3Be3B3O9F4									[31]
NaSr3Be3B3O9F4									[32]
K3Sr3Li2Al4B6O20F								SHG 4 × KDP; 170 nm UV cutoff	[9]
Ca(Y,REE,Ca,Na,Mn)15Fe2+(P,Si)Si6B3O34F14	Proshchenkoite-(Y)		trigonal	R3m	a = 10.7527, c = 27.4002	2,743.6		brownish	[33]
(Y,REE,Ca,Na)15(Al,Fe3+)(CaxAs3+1−x)(Si,As5+)Si6B3(O,F)48	Hundholmenite-(Y)		trigonal	R3m	a = 10.675, c = 27.02 Z=3	2,667		density 5.206 brownish Uniaxial (-)	[34]
(Na,Ca)3(Y,Ce)12Si6B2O27F14	Okanoganite-(Y)		trigonal	R3m	a = 10.7108, c = 27.040		4.35	Tan coloured Uniaxial (-) nω = 1.753 nε = 1.740 Max birefringence δ = 0.013	[35]
? Y5(SiO4,BO4)3(O,OH,F)	Tritomite-(Y)		?hexagonal		a = 9.32, c = 6.84		3.05-3.4	isotropic n = 1.627 - 1.685
Cd8B5O15F		1212.25	cubic	Fd3m	a = 13.972 Z = 8	2,727	5.904	colourless	[36]
CdZn2KB2O6F
Li3Cs6Al2B14O28F		1490.58	orthorhombic	Pnma	a=21.8412 b=19.8875 c=7.1577 Z=4	3109.1	3.184		[37]
CsBe2BO3F2		247.74	trigonal	R32	a=4.4575 c=21.310 Z=3	366.7	3.366	colourless	[38]
Cs18Mg6(B5O10)3(B7O14)2F			monoclinic	C2/c	a=11.234 b=20.11 c=32.12 β=90.225°				[29]
CsCaBe2B2O6F			trigonal	R32					[39]
BaBOF3		221.15	monoclinic	P21/c	a = 4.620 b = 15.186 c = 4.426 β = 92.045° Z=4	310.3		contains chains of -OB(F2)- and a double chain of BaF	[40]
Ba5(BO3)3F									[41]
Li2BaSc(BO3)2F		332.80	hexagonal	P63/m	a=4.895 c=14.346	297.7	3.713		[42]
LiBa12(BO3)7F4				I4/mcm
BaBe2BO3F3		271.16	hexagonal	P63	a=7.628 c=13.990 Z=6	704.9	3.832	UV cutoff <185 nm; birefringence 0,081 at 200 nm	[43]
NaBa12(BO3)7F4				I4/mcm
BaMgBe2(BO3)2F2	BMBBF	335.283	trigonal	P3c1	a=4.5898 c=15.348	280.01	3.976	colourless [Be2B3O6F2]∞	[44]
Ba3.75MgB7O14F2.5		886.50	monoclinic	C2/c	a 16.611 b 13.677 c 15.141 β 121.239° Z=8	2941.0	4.004	transparent > 203 nm; birefringence 0.081@546 nm	[45]
BaAl(BO3)F2			hexagonal	P6	a=4.8879 c=9.403 Z=2	194.5		UV cutoff 165 nm	[46]
K3Ba3Li2Al4B6O20F									[9]
K5Ba10(BO3)8F			trigonal	R3c	a = 15.293, c = 22.699 Z = 6				[47]
KBa7Mg2B14O28F5			monoclinic	C2/c	a = 16.638 b = 13.609 c = 15.214 β = 121.309° Z=4	2943.3	3.934	colourless	[48]
BaCaBe2(BO3)2F2	BCBBF		trigonal	P3c1	a=4.6931 c=16.049	306.12	3.808	colourless [Be2B3O6F2]∞	[44]
Li2BaSc(BO3)2F			hexagonal	P63/m	a=4.895 c=14.346				[49]
Ba3Zn(BO3)(B2O5)F		656.82	monoclinic	P21/c	a = 15.179 b = 7.0064 c = 8.763 β = 100.15° Z=4	917.4	4.755	colourless	[50]
Ba4Zn2(BO3)2(B2O5)F2		937.34	monoclinic	C2/c	a=20.39 b=4.998 c=13.068 β = 192.59 Z=44	1,331	4.679	colourless	[50]
BaZnBe2(BO3)2F2		376.35	trigonal	P3	a = 4.5998, c = 7.7037 Z = 1	141.16	4.427	colourless	[51]
Rb3Ba3Li2Al4B6O20F									[9]
BaCdBe2(BO3)2F2	BDBBF			P3c1	a=4.6808 c=15.788				[8]
Ba1.09Pb0.91Be2(BO3)2F2	BPBBF		trigonal	P3m1	a = 4.7478 c = 8.386, Z = 1	163.70		UV absorption edge=279.1 nm; birefringence 0.054 at 546.1 nm; 2D [Be3B3O6F3]∞ layer	[52]
LiBa2Pb(BO3)2F			orthorhombic	Pmmn	a=5.487 b=15.96 c=4.034				[49]
KNa3Na6Ca2Ba6Mn6(Ti4+,Nb)6B12Si36O114(O,OH,F)11	Tienshanite		hexagonal	P6/m	a = 16.785, c = 10.454 Z=1	2,551		pale olive green Uniaxial (-) nω = 1.666 nε = 1.653 Max birefringence δ = 0.013	[53]
Ca6(Fe2+,Mn2+)Y3REE7(SiO4)3(PO4)(B3Si3O18)(BO3)F11	Laptevite-(Ce)		trigonal	R3m	a = 10.804, c = 27.726 Z=3	2,803		density 4.61 dark brown Uniaxial (-) nω = 1.741(3) nε = 1.720(3) Max birefringence δ = 0.021	[54]
Ba(Y,Ce)6Si3B6O24F2	Cappelenite-(Y)		trigonal	P3	a = 10.67, c = 4.68 Z=1	461	4.407	greenish brown	[55]
CaMg[(Ce7Y3)Ca5](SiO4)4(Si2B3AsO18)(BO3)F11	Arrheniusite-(Ce)		trigonal	R3m	a = 10.8082, c = 27.5196				[56]
Gd4(BO2)O5F			orthorhombic	Pmmn	a=15.746 b=3.8142 c=6.609 Z=2	396.9	6.45	colourless	[57]
Gd2(BO3)F3
Gd3(BO3)2F3
Gd4[B4O11]F2
Ba2Gd(BO3)2F			orthorhombic	Pnma	a = 7.571 b = 10.424 c = 8.581 Z = 2				[58]
Eu5(BO3)3F			orthorhombic	Pnma	a=7.225 b=14.124 c=9.859 Z=4	1006.1	6.306	yellow	[59]
TlBe2BO3F2			Trigonal	R32	a=4.4387 c=19.942 Z=3	340.27	4.673	colourless	[60]
LiBa2Pb(BO3)2F			orthorhombic	Pmmn	a=5.487 b=15.97 c=4.034	353.4	5.887	colourless	[61]
(Ca,Ce,La,Th)15As5+(As3+0.5,Na0.5)Fe3+Si6B4O40F7	Vicanite-(Ce)		trigonal	R3m	a=10.881 c=27.33	2,766	4.82	greenish yellow Uniaxial (-) nω = 1.757 nε = 1.722 Max birefringence δ = 0.035	[62]