The borate chlorides are chemical compounds that contain both borate ions and chloride ions. They are mixed anion compounds. Many of them are minerals. Those minerals that crystallise with water (hydrates) may be found in evaporite deposits formed when mineral water has dried out.
Chemical formula | Molar mass (g/mol) | Crystal system | Space group | Unit cell (Å) | Volume (Å3) | Density (g/cm3) | Comment | References | |
---|---|---|---|---|---|---|---|---|---|
Teepleite | Na2[B(OH)4]Cl | tetragonal | P4/nmm | a = 7.25, c = 4.84 | 254.4 | 2.076 | Colourless, white or light beige crystals, with a vitreous, greasy, or dull lustre. Uniaxial (-) nω = 1.519 nε = 1.503 Max birefringence δ = 0.016 | [1] | |
Boracite | Mg3(B7O13)Cl | orthorhombic | Pca21 | a = 8.577, b = 8.553, c = 12.09 Z=4 | 992.5 | 2.95 | Green, dark green (ferroan), blue, colourless, grey or white crystals with an adamantine, vitreous lustre if transparent. Biaxial (+) nα = 1.658 - 1.662 nβ = 1.662 - 1.667 nγ = 1.668 - 1.673 2V 82° Max birefringence δ = 0.010 - 0.011 | [2] | |
Karlite | Mg7(BO3)3(OH,Cl)5 | orthorhombic | a = 17.92, b = 17.6, c = 3.1 | 978 | 2.80 | White to light green crystals with a silky lustre. Biaxial (-) nα = 1.589 nβ = 1.632 nγ = 1.634 2V 24° Max birefringence δ = 0.045 | [3] | ||
Shabynite | Mg5(BO3)(OH)5(Cl,OH)2·4H2O | monoclinic | 2.32 | Colourless or white crystals with a silky lustre. Biaxial (-) nα = 1.543 nβ = 1.571 nγ = 1.577 2V 49° Max birefringence δ = 0.034 | [4] | ||||
Satimolite | KNa2Mg2Al5[B12O18(OH)12](OH)6Cl4·4H2O | trigonal | R3m | a = 15.1431, c = 14.456 Z=3 | 2.1 | White to colorless crystals with a vitreous or dull lustre. Biaxial (-) nα = 1.535 nβ = 1.552 nγ = 1.553 2V 26° Max birefringence δ = 0.018 | [5] [6] | ||
Kalborsite | K6Al4BSi6O20(OH)4Cl | Tetragonal | a = 9.85, c = 13.06 | 1,267 | 2.5 | Colorless with a slight rose-brownish tint crystals with a vitreous or pearly lustre. Uniaxial (+) nω = 1.525 nε = 1.525 ? Max birefringence δ = 0.000 | [7] | ||
Hilgardite | Ca2B5O9Cl·H2O | triclinic | P1 | a=6.463 b=6.564 c=6.302 α = 61°38', β = 118°46', γ = 105°47' Z=1 | 205.8 | 2.67 to 2.71 | Colorless, light pink crystals with a vitreous lustre. | [8] | |
Solongoite | Ca2(H3B3O7)(OH)Cl | monoclinic | a = 7.93, b = 7.26, c = 12.54 β = 94° | 720 | 2.514 | Colourless crystals with a vitreous lustre. Biaxial (+) nα = 1.510 nβ = 1.510 nγ = 1.545 Max birefringence δ = 0.035 | [9] | ||
Ekaterinite | Ca2(B4O7)(Cl,OH)2·2H2O | hexagonal | a = 11.86, c = 23.88 | 2,909 | 2.440 | White or white with slight rose tint crystals with a pearly lustre. Uniaxial (-) nω = 1.577 nε = 1.574 Max birefringence δ = 0.003 | [10] | ||
Chelkarite | CaMgB2O4(Cl,OH)2·5H2O or near Cl:OH = 3:1 | orthorhombic | a = 13.69, b = 20.84, c = 8.26 | 2,357 | 2.21 | Colorless crystals. Biaxial (+) nα = 1.520 nγ = 1.558 Max birefringence δ = 0.038 | [11] | ||
Sakhaite | Ca48Mg16(BO3)32(CO3)16·2(H2O,HCl) | isometric | Fd3m | a = 14.685 Z=4 | 3166.8 | 2.78 - 2.83 | Colourless, gray to grayish white crystals with a greasy lustre. | [12] | |
Hydrochlorborite | Ca4B8O15Cl2·21H2O | monoclinic | a = 22.78, b = 8.74, c = 17.06 β = 96.7° | 3373 | 1.83 - 1.85 | Colorless crystals with a vitreous, dull lustre. Biaxial (+) nα = 1.499 nβ = 1.502 nγ = 1.521 2V 45° Max birefringence δ = 0.022 | [13] | ||
Heidornite | Na2Ca3B5O8(OH)2(SO4)2Cl | monoclinic | C2/c | a = 10.19, b = 7.76, c = 18.81 β = 93.33° Z=4 | 1,485 | 2.753 | Colorless crystals with a vitreous lustre. Biaxial (+) nα = 1.579 nβ = 1.588 nγ = 1.604 2V 63° to 77° Max birefringence δ = 0.025 | [14] | |
Volkovskite | KCa4[B5O8OH]4[B(OH)3]2Cl·4H2O | triclinic | P1 | a = 6.57, b = 23.92, c = 6.52 α = 90.58°, β = 119.1°, γ = 95.56° | 889.2 | 2.27 | Colourless or pink; varying from pale to deep orange crystals with a vitreous lustre. Biaxial (+) nα = 1.523 - 1.539 nβ = 1.539 - 1.540 nγ = 1.596 - 1.605 2V 14.6° Max birefringence δ = 0.073 | [15] | |
Kurgantaite | CaSr[B5O9]Cl·H2O | triclinic | P1 | a = 6.5732, b = 6.4445, c = 6.3693, α = 60.995°, β = 61.257°, γ = 77.191° Z=1 | 2.99 | Colourless to white crystals with a vitreous lustre. | [16] | ||
Chambersite | (Mn2+)3(B7O13)Cl | orthorhombic | Pca21 | a = 8.68, b = 8.68, c = 12.26 Z=4 | 924 | 3.49 | Colorless to deep purple crystals with a vitreous lustre. Biaxial (+) nα = 1.732 nβ = 1.737 nγ = 1.744 2V 83° Max birefringence δ = 0.012 | [17] | |
Ericaite | (Fe2+)3(B7O13)Cl | orthorhombic | a = 8.58, b = 8.65, c = 12.17 | 903 | 3.17 - 3.27 | Red, green, purple, brown or black crystals. Biaxial (-) nα = 1.731 nβ = 1.755 nγ = 1.755 Max birefringence δ = 0.024 | [18] | ||
Congolite | (Fe2+,Mg)3[B7O13]Cl | trigonal | R3c | a = 8.62, c = 21.05 | 1355 | 3.58 | Pale red or pink crystals. Uniaxial (-) nω = 1.755 nε = 1.731 Max birefringence δ = 0.024 | [19] | |
Trembathite | (Mg,Fe2+)3[B7O13]Cl | trigonal | a = 8.57, c = 20.99 | 1335 | 2.84 - 3.34 | Colourless to pale blue transparent crystals with a vitreous lustre. Uniaxial (-) nω = 1.684 nε = 1.668 Max birefringence δ = 0.016 | [20] [21] | ||
Bandylite | Cu2+[B(OH)4]Cl | tetragonal | P4/nmm | a = 6.19 Å, c = 5.61 Z=2 | 214.9 | 2.81 | Deep blue crystals with greenish portions; cendre blue to Italian blue, becoming greener with atacamite inclusions, with a vitreous or pearly lustre. Uniaxial (-) nω = 1.691 - 1.692 nε = 1.640 - 1.641 Max birefringence δ = 0.051 | [22] | |
Li3B8O13Cl | 350.75 | Otrhorhombic | Pca21 | a=17.229 b=9.3827 c=6.6452 Z=4 | 1074.25 | 2.169 | birefringence 0.094 at 1064 nm | [23] | |
Na4[B6O9(OH)3](H2O)Cl | Otrhorhombic | Pca21 | a=15.4867 b=8.6867 c=8.8551 Z=2 | 1191.3 | 2.260 | SHG 0.4 × KDP | [24] | ||
Mg3B7O13Cl[ clarification needed ] | 392.05 | orthorhombic | Pca21 | a=8.5319 b=8.5282 c=12.0730 Z=4 | 878.45 | 2.964 | NLO | [25] | |
KZn2BO3Cl2 | trigonal | R32 | NLO SHG 1.3 × KDP | [26] | |||||
Ag4B7O12Cl | 734.6 | triclinic | P1 | a=8.7394 b=8.7881 c=9.1381 α=65.625° β=77.269° γ=61.173° Z=2 | 562 | [27] | |||
RbZn2BO3Cl2 | 345.92 | trigonal | R32 | a=4.965 c=27.21 | NLO SHG 1.17 × KDP | [26] | |||
Sn3B10O17Cl2 | orthorhombic | Pbcn | a =19.1905 b=10.3893 c=8.5164 | UV cutoff 280 nm; birefringence 0.125 at 546 nm | [28] | ||||
Ba6BO3Cl9 | 1201.90 | monoclinic | P21/n | a=8.229 b=12.259 c=19.080 β=90.20 Z=4 | 1924.7 | 4.418 | colourless | [29] | |
NaBa4Al2B8O18Cl3 | tetragonal | P42nm | a = 12.048, c = 6.817 | NLO | [30] | ||||
NaBa4(GaB4O9)2Cl3 | 1192.62 | tetragonal | P42nm | a=12.1033 c=6.8329 Z=2 | 1001.0 | 3.957 | SHG 1.5xKDP | [31] | |
Rb4Ba2.5B20O34Cl | 1481.10 | triclinic | P1 | a=6.756 b=11.086 c=11.288 α=99.07° β=90.60° γ=100.38° Z=1 | 820.6 | 2.9965 | colourless | [32] | |
La(BO2)2Cl | triclinic | [33] | |||||||
Cs2La2B10O17Cl4 | 1065.54 | monoclinic | Cm | a=8.6904 b=20.92 c=6.4231 β =104.003 Z=2 | 1126.15 | 3.142 | SHG 2.1xKDP | [34] | |
Ce(BO2)2Cl | triclinic | P1 | a = 4.2174; b = 6.5763; c = 8.1221 α = 82, 152; β = 89, 206; γ = 72.048°; Z = 2 | [33] | |||||
Ce3[BO3]2Cl3 | hexagonal | P63/m | a = 9.2008, c = 5.8079; Z = 2 | [33] | |||||
Pr(BO2)2Cl | triclinic | [33] | |||||||
Sm4[B16O26(OH)4(H2O)3Cl4] | [35] | ||||||||
Eu4[B16O26(OH)4(H2O)3Cl4] | [35] | ||||||||
Gd4[B16O26(OH)4(H2O)3Cl4] | [35] | ||||||||
Pb6BO4Cl7 | 1566 | triclinic | P1 | a=8.001 b=8.054 c=13.116 α=89.52 β=89.66 γ=69.942 | 793.9 | 6.551 | colourless | [29] | |
Pu[B4O6(OH)2Cl] | monoclinic | Cc | a=6.4898 b=11.174 c=9.6183 β=105.15° | [36] | |||||
Pu2[B13O19(OH)5Cl2(H2O)3] | monoclinic | P21/n | a=8.0522 b=14.568 c=9.82 β=90.12° | [36] | |||||
Pu4[B16O26(OH)4(H2O)3Cl4] | [35] | ||||||||
Am[B9O13(OH)4]·H2O | monoclinic | P21/n | a=7.703Å b=16.688Å c=9.872 β=90.073° | [36] | |||||
Am4[B16O26(OH)4(H2O)3Cl4] | [35] | ||||||||
Cm2[B14O20(OH)7(H2O)2Cl] | monoclinic | P21/n | a=7.9561 b=14.212 c=9.836 β=90.013° | [36] | |||||
Cm4[B16O26(OH)4(H2O)3Cl4] | [35] | ||||||||
Cf4[B16O26(OH)4(H2O)3Cl4] | [35] |
Fluorooxoborate is one of a series of anions or salts that contain boron linked to both oxygen and fluorine. Several structures are possible, rings, or chains. They contain [BOxF4−x](x+1)− units BOF32− BO2F23−, or BO3F14−. In addition there can be borate BO3 triangles and BO4 tetrahedrons. These can then be linked by sharing oxygen atoms, and when they do that, the negative charge is reduced. They are distinct from the fluoroborates in which fluorine is bonded to the metals rather than the boron atoms. For example, KBBF, KBe2BO3F2 is a fluoroborate and has more fluorine and oxygen than can be accommodated by the boron atom.
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.
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.
The borate carbonates are mixed anion compounds containing both borate and carbonate ions. Compared to mixed anion compounds containing halides, these are quite rare. They are hard to make, requiring higher temperatures, which are likely to decompose carbonate to carbon dioxide. The reason for the difficulty of formation is that when entering a crystal lattice, the anions have to be correctly located, and correctly oriented. They are also known as carbonatoborates or borocarbonates. Although these compounds have been termed carboborate, that word also refers to the C=B=C5− anion, or CB11H12− anion. This last anion should be called 1-carba-closo-dodecaborate or monocarba-closo-dodecaborate.
The iodate fluorides are chemical compounds which contain both iodate and fluoride anions (IO3− and F−). In these compounds fluorine is not bound to iodine as it is in fluoroiodates.
The sulfate fluorides are double salts that contain both sulfate and fluoride anions. They are in the class of mixed anion compounds. Some of these minerals are deposited in fumaroles.
The borosulfates are heteropoly anion compounds which have sulfate groups attached to boron atoms. Other possible terms are sulfatoborates or boron-sulfur oxides. The ratio of sulfate to borate reflects the degree of condensation. With [B(SO4)4]5- there is no condensation, each ion stands alone. In [B(SO4)3]3- the anions are linked into a chain, a chain of loops, or as [B2(SO4)6]6− in a cycle. Finally in [B(SO4)2]− the sulfate and borate tetrahedra are all linked into a two or three-dimensional network. These arrangements of oxygen around boron and sulfur can have forms resembling silicates. The first borosulfate to be discovered was K5[B(SO4)4] in 2012. Over 75 unique compounds are known.
The borophosphates are mixed anion compounds containing borate and phosphate anions, which may be joined together by a common oxygen atom. Compounds that contain water or hydroxy groups can also be included in the class of compounds.
The borotellurates are heteropoly anion compounds which have tellurate groups attached to boron atoms. The ratio of tellurate to borate reflects the degree of condensation. In [TeO4(BO3)2]8- the anions are linked into a chain. In [TeO2(BO3)4]10− the structure is zero dimensional with isolated anions. These arrangements of oxygen around boron and tellurium can have forms resembling silicates. The first borotellurates to be discovered were the mixed sodium rare earth compounds in 2015.
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.
Borate sulfides are chemical mixed anion compounds that contain any kind of borate and sulfide ions. They are distinct from thioborates in which sulfur atoms replace oxygen in borates. There are also analogous borate selenides, with selenium ions instead of sulfur.
Borate phosphates are mixed anion compounds containing separate borate and phosphate anions. They are distinct from the borophosphates where the borate is linked to a phosphate via a common oxygen atom. The borate phosphates have a higher ratio of cations to number of borates and phosphates, as compared to the borophosphates.
The borate bromides are mixed anion compounds that contain borate and bromide anions. They are in the borate halide family of compounds which also includes borate fluorides, borate chlorides, and borate iodides.
The borate iodides are mixed anion compounds that contain both borate and iodide anions. They are in the borate halide family of compounds which also includes borate fluorides, borate chlorides, and borate bromides.
Selenide borates, officially known as borate selenides, are chemical mixed anion compounds that contain any kind of borate and selenide ions. They are distinct from selenoborates in which selenium atoms replace oxygen in borates. There are also analogous borate sulfides, with sulfur ions instead of selenium.
Selenogallates are chemical compounds which contain anionic units of selenium connected to gallium. They can be considered as gallates where selenium substitutes for oxygen. Similar compounds include the thiogallates and selenostannates. They are in the category of chalcogenotrielates or more broadly chalcogenometallates.
Sulfidostannates, or thiostannates are chemical compounds containing anions composed of tin linked with sulfur. They can be considered as stannates with sulfur substituting for oxygen. Related compounds include the thiosilicates, and thiogermanates, and by varying the chalcogen: selenostannates, and tellurostannates. Oxothiostannates have oxygen in addition to sulfur. Thiostannates can be classed as chalcogenidometalates, thiometallates, chalcogenidotetrelates, thiotetrelates, and chalcogenidostannates. Tin is almost always in the +4 oxidation state in thiostannates, although a couple of mixed sulfides in the +2 state are known,
Selenidogermanates are compounds with anions with selenium bound to germanium. They are analogous with germanates, thiogermanates, and telluridogermanates.
A fluorooxoiodate or fluoroiodate is a chemical compound or ion derived from iodate, by substituting some of the oxygen by fluorine. They have iodine in the +5 oxidation state. The iodine atoms have a stereochemically active lone-pair of electrons. Many are non-centrosymmetric, and are second harmonic generators (SHG) of intense light shining through them. They are under investigation as materials for non-linear optics, such as for generating ultraviolet light from visible or infrared lasers.
When values of birefingence are very high, the property is termed giant birefringence which more generically is called giant optical anisotropy. Values for giant birefringence exceed 0.3. Much bigger numbers are termed "colossal birefringence". These are achieved using nanostructures.