An arsenate arsenite is a chemical compound or salt that contains arsenate and arsenite anions ( and ). These are mixed anion compounds or mixed valence compounds. Some have third anions. Most known substances are minerals, but a few artificial arsenate arsenite compounds have been made. Many of the minerals are in the Hematolite Group.
An arsenate arsenite compound may also be called an arsenite arsenate.
Properties Some members of this group of materials like mcgovernite has an extremely high unit cell dimension of 204 Å.
Related Mixed valence pnictide compounds related to the arsenate arsenites include the nitrite nitrates, and phosphate phosphites.
List nameformularatio :systemspace groupunit cell ÅvolumedensitypropertiesreferencesArsenic dioxideAsO21:1orthorhomnicPnmaa=8.597 b=5.235 c=7.269 Z=8327.14.382Arsenic(III) Arsenic(V) Oxide HydroxideAs3O5(OH)1:2monoclinicP21/ca = 12.504 b = 4.593 c = 10.976 β = 118.08° Z = 4 556.23.84H6As3+7As5+7O311:1hexagonalP63a = 12.0525 c = 4.7344 Z = 2595.6SegerstromiteCa3(As5+O4)2[As3+(OH)3]22:1cubicI213a = 10.7627 Z = 41246.713.46colourless; refract index: n = 1.731SynadelphiteMn2+9(As5+O4)2(As3+O3)(OH)9 · 2H2O2:1OrthorhombicPnmaa = 10.75 b = 18.86c = 9.88 Z=420053.58red; Biaxial (+); refract index: nα = 1.750–1.870 nβ = 1.751–1.880 nγ = 1.761–1.930Hematolite(Mn,Mg,Al,Fe3+)15(As5+O4)2(As3+O3)(OH)232:1trigonalRa = 8.275 Å, c = 36.60 Å Z=32,170.43.49deep red; Uniaxial (−) refractive index nω = 1.733 nε = 1.714; Birefringence: 0.019Turtmannite(Mn,Mg)22.5Mg3-3x((V5+,As5+)O4)3(As3+O3)x(SiO4)3O5-5x(OH)20+xtrigonala = 8.259 c = 204.3 Z=1212,0683.8light yellow; Uniaxial(−); refractive index: nε = 1.787CarlfrancisiteMn2+3(Mn2+,Mg,Fe3+,Al)42[As3+O3]2(As5+O4)4[(Si,As5+)O4]6[(As5+,Si)O4]2(OH)42trigonalRca = 8.2238 c = 205.113 Z=612,013.53.620yellow-orange; Uniaxial (+) refractive index: nω = 1.756(2) nε = 1.758 Birefringence: δ = 0.002K2Cu3(As2O6)21:1monoclinicC2ma=10.359 b=5.388 c=11.234 β=110.48°[As(V)As(III)O6]4−DixeniteCuMn2+14Fe2+(SiO4)2(As5+O4)(As3+O3)5(OH)61:5trigonalR3a = 8.233 c = 37.499 Z=322014.35deep red-brown; Uniaxial (+) refractive index nω = 1.970 nε = 1.730Arakiite(Zn,Mn2+)(Mn2+,Mg)12(Fe3+,Al)2(As5+O4)2(As3+O3)(OH)232:1monoclinicCca = 14.248 b = 8.228 c = 24.23 β = 93.62° Z=428433.41orange-red brown; Biaxial(−); refract index: nα = 1.723 nβ = 1.744 nγ = 1.750 Birefringence: 0.027KraissliteZn3(Mn,Mg)25(Fe3+,Al)(As3+O3)2[(Si,As5+)O4]10(OH)165:1OrthorhombicC2221a = 8.1821 b = 14.1946 c = 43.9103 Z=45099.83.876pale red; Uniaxial (+) Refractive index: nε = 1.805McgoverniteMn19Zn3(AsO4)3(AsO3)(SiO4)3(OH)213:1trigonalR3m or Rma = 8.22 c = 203.1 Z=611,887.523.719brown; Uniaxial (+) Refractive index: nω = 1.757 nε = 1.760 Birefringence: δ = 0.003Halilsarpite[Mg(H2O)6][CaAs3+2(Fe3+2.67Mo6+0.33)(AsO4)2O7]orthorhomnicImmaa = 26.489 b = 7.4205 c = 10.4378 2051.7lemon yellow; Biaxial(−) refractive index: nα = 1.646 nβ = 1.765(5) nγ = 1.815(5) 2V: 62° Max Birefringence: δ = 0.169WiklunditePb2(Mn2+,Zn)3(Fe3+,Mn2+)2(Mn2+,Mg)19(As3+O3)2[(Si,As5+)O4]6(OH)18Cl6hexagonal? Rca = 8.257 c = 126.59 Z = 674744.072dark reddish brownBi8O6(AsO3)2(AsO4)2monoclinicI2/aa=24.372 b=5.528 c=29.90 β=99.058 Z=839787.652colourlessTh(AsIII4AsV4O18)1:1monoclinicC2/ca=18.2148 b 5.19792 c=17.3588 β=99.1298 Z=41622.704.582colourless
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