according to E.H. Nickel & M.C. Nichols (2009), H. Strunz & E.H. Nickel (2001)

(Oxides, Hydroxides, V[5,6]-Vanadates, Arsenites, Antimonites, Bismutites, Sulfites, Selenites, Tellurites, Iodates)

4.F: Hydroxides

4.FA. Hydroxides with OH, without H2O; corner-sharing tetrahedra
4.FA.05. Behoite group
     05 a. Behoite series
Behoite Be(OH)2 orth., P212121 FOTO     IMA 1969-031

     05 b. Clinobehoite series
Clinobehoite Be(OH)2 mon., P21 IMA 1988-024

4.FA.10. Wülfingite group
Wülfingite Zn(OH)2 orth., P212121 FOTOIMA 1983-070
Sweetite Zn(OH)2 tetr., P41212 (?) FOTOIMA 1983-011
Ashoverite Zn(OH)2 tetr., P41/amd (?) FOTOIMA 1986-008

4.FB. Hydroxides with OH, without H2O; insular octahedra
4.FB.05. Sakhovite group
Sakhovite Hg4SbO3(OH)3 mon., Im IMA 1980-069

4.FB.10. Cualstibite group
Cualstibite Cu2AlSb(OH)12 trig. IMA 1983-068
Zincalstibite Zn2AlSb(OH)12 trig., P-3 IMA 1998-033

4.FC. Hydroxides with OH, without H2O; framework of corner-sharing octahedra
4.FC.05. Söhngeite group
Söhngeite Ga(OH)3 cub., Im-3 FOTOIMA 1965-022
Dzhalindite In(OH)3 cub., Im-3 A
Bernalite Fe(OH)3 orth., Immm IMA 1991-032

4.FC.10. Schoenfliesite group
Schoenfliesite MgSn(OH)6 cub., Pn-3 IMA 1968-008
Natanite FeSn(OH)6 cub., Pn-3 FOTOIMA 1980-028
Wickmanite FeSn(OH)6 cub., Pn-3 IMA 1965-024
Mushistonite CuSn(OH)6 cub., Pn-3m FOTOIMA 1982-068
Vismirnovite ZnSn(OH)6 cub., Pn-3m IMA 1980-029
Burtite CaSn(OH)6 cub., Pn-3 IMA 1980-078

4.FC.15. Stottite group
Stottite FeGe(OH)6 tetr., P42/n G
Jeanbandyite FeSn(OH)6 tetr., P42/n FOTOIMA 1980-043
Tetrawickmanite MnSn(OH)6 tetr., P42/n FOTOIMA 1971-018
Mopungite NaSb(OH)6 tetr., P42/n FOTOIMA 1982-020

4.FC.20. Nigerite group
Ferronigerite-2N1S (Al,Fe,Zn)2(Al,Sn)6O11(OH) trig., P-3m1 Rn
Ferronigerite-6N6S (Al,Fe,Zn)3(Al,Sn,Fe)8O15(OH) trig., R-3m FOTORn
Magnesionigerite-2N1S (Mg,Al,Zn)2(Al,Sn)6O11(OH) trig., P-3m1 IMA 1988-010, Rn
Magnesionigerite-6N6S (Mg,Al,Zn)3(Al,Sn,Fe)8O15(OH) trig., Rn
Zinconigerite-2N1S (Zn,Al,Fe)2(Al,Fe)6O11(OH) trig. H
Zinconigerite-6N6S (Zn,Al,Fe)3(Al,Fe)8O15(OH) trig., R-3m N

Ferronigerite-2N1S, originally described as Nigerite, renamed (2002).
Ferronigerite-6N6S, originally described as Nigerite-24R, renamed (2002).
Magnesionigerite-2N1S, originally described as Pengzhizhongite-6R, renamed (2002).
Magnesionigerite-6N6S, originally described as Pengzhizhongite-24R, renamed (2002).

4.FC.25. Taaffeite group
Magnesiotaaffeite-2N'2S BeMg3Al8O16 hex., P63mc Rn
Magnesiotaaffeite-6N'3S BeMg2Al6O12 trig., R-3m IMARn
Ferrotaaffeite-2N'3S BeFe3Al8O16 hex., P63mc IMA 2011-025
Ferrotaaffeite-6N'3S BeFe2Al6O12 trig., R-3m Rn

Magnesiotaaffeite-2N'2S, originally described as Taaffeite, renamed.
Magnesiotaaffeite-6N'3S, originally described as Musgravite, renamed.
Ferrotaaffeite-6N'3S, originally described as Pehrmanite, renamed.

4.FD. Hydroxides with OH, without H2O; chains of edge-sharing octahedra
4.FD.05. Spertiniite group
Spertiniite Cu(OH)2 orth., Cmc21 IMA 1980-033

4.FD.10. Diaspore group
Diaspore AlO(OH) . orth., Pbnm G
Goethite FeO(OH) . orth., Pbnm A
Groutite MnO(OH) . orth., Pbnm G
Montroseite VO(OH) . orth., Pbnm FOTOG
Bracewellite CrO(OH) . orth., Pbnm IMA 1967-035
Guyanaite CrO(OH) . orth., Pnnm IMA 1967-034
Tsumgallite GaO(OH) . orth., Pbnm IMA 2002-011

4.FD.15. Manganite group
Manganite MnO(OH) mon., B21/d FOTO ENTDECKUNGG

4.FD.20. Yttrotungstite group
Yttrotungstite-(Y) Y(W,Fe,Si,Al)2(O,OH,H2O)9 mon., P21/m FOTOA
Yttrotungstite-(Ce) CeW2O6(OH)3 mon., P21/m or P21 IMA 1970-008, Rn

4.FD.25. Frankhawthorneite group
Frankhawthorneite Cu2Te6+O4(OH)2 mon., P21/n IMA 1993-047

4.FD.30. Khinite group
Khinite   (Khinite-4O) Cu3PbTeO4(OH)6 orth., Fddd IMA 1978-035
    Khinite-3T Cu3PbTeO6(OH)2 trig., P32 Poly

Khinite-3T was originally described as parakhinite (IMA 1978-036), redefined 2009 as a polytype of khinite.

4.FE. Hydroxides with OH, without H2O; sheets of edge-sharing octahedra
4.FE.05. Brucite group
Brucite Mg(OH)2 trig., P-3m1 FOTOG
Pyrochroite Mn(OH)2 trig., P-3m1 FOTOG
Amakinite Fe(OH)2 trig., P-3m1 A
Theophrastite Ni(OH)2 trig., P-3m1 A
Portlandite Ca(OH)2 trig., P-3m1 FOTOG

Nickel & Nichols (2009) placed fougèrite, [Fe2+6Fe3+2(OH)16][(OH)2 · 4 H2O], in the brucite group, but fougèrite is a LDH with a hydrotalcite-like structure and the Fe2+-Fe3+ analogue of meixnerite and classified here accordingly in the group 4.FL.05.

4.FE.10. Gibbsite group
Gibbsite Al(OH)3 mon., P21/n FOTOA
Bayerite Al(OH)3 mon., P21/n G
Doyleite Al(OH)3 tric., P-1 IMA 1980-041
Nordstrandite Al(OH)3 tric., I-1 FOTOA

4.FE.15. Böhmite group
Böhmite AlOOH orth., Cmcm G
Lepidocrocite  /  Lepidokrokit FeOOH orth., Cmc21 A

4.FE.20. Heterogenite group
Heterogenite   (-3R) CoOOH trig., R-3m FOTOENTDECKUNGA
     Heterogenite-2H CoOOH hex., P63/mmc Poly
Grimaldiite CrOOH trig., R-3m IMA 1967-036

4.FE.25. Lithiophorite group
Lithiophorite (Al,Li)Mn4+O2(OH)2 trig., R-3m FOTOENTDECKUNGG
Feitknechtite MnOOH trig., P-3m1 A

4.FE.30. Quenselite group
Quenselite PbMn3+O2(OH) mon., P2/a G

4.FE.35. Ferrihydrite group
Ferrihydrite Fe4 - 5(OH,O)12 hex. FOTOIMA 1971-015

4.FE.40. Feroxyhyte group
Feroxyhyte FeOOH hex. IMA 1975-032
Vernadite (Mn,Fe,Ca,Na)(O,OH)2 · n H2O hex. Q

4.FE.45. Quetzalcoatlite group
Quetzalcoatlite Cu3Zn6Te2O12(OH)6 · (Ag,Pb,□)Cl trig., P-31m FOTOIMA 1973-010

4.FF. Hydroxides with OH, without H2O; various polyhedra
4.FF.05. Hydroromarchite group
Hydroromarchite Sn3O2(OH)2 tetr., P-421c IMA 1969-007

4.FG. Hydroxides with OH, without H2O; unclassified
4.FG.05. Janggunite group
Janggunite (Mn4+,Mn2+,Fe3+>)6O8(OH)6 orth. IMA 1975-011

4.FG.10. Cesàrolite group
Cesàrolite PbMn4+3O6(OH)2 hex. G

4.FG.15. Kimrobinsonite group
Kimrobinsonite Ta(OH)3(O,CO3) cub. IMA 1983-023

4.FH. Hydroxides with H2O +/- (OH); insular octahedra
4.FH.05. Bottinoite group
Bottinoite NiSb2(OH)12 · 6 H2O trig., P3 IMA 1991-029
Brandholzite MgSb2(OH)12 · 6 H2O trig., P3 IMA 1998-017

4.FJ. Hydroxides with H2O +/- (OH); corner-sharing octahedra
4.FJ.05. Sidwillite group
Sidwillite MoO3 · 2 H2O mon., P21/n IMA 1983-089
Meymacite WO3 · 2 H2O amorphous FOTORd

4.FJ.10. Tungstite group
Tungstite WO3 · H2O orth., Pmnb FOTOG

4.FJ.15. Hydrotungstite group
Hydrotungstite WO2(OH)2 · H2O mon. G
Ilsemannite Mo3O8 · n H2O (?) amorphous FOTOQ

4.FJ.20. Parabariomicrolite group
Parabariomicrolite BaTa4(OH)2O10 · 2 H2O trig., R-3m IMA 1984-003

4.FK. Hydroxides with H2O +/- (OH); chains of edge-sharing octahedra
4.FK.05. Bamfordite group
Bamfordite FeMo2O6(OH)3 · H2O tric., P1 or P-1 IMA 1996-059

4.FL. Hydroxides with H2O +/- (OH); sheets of edge-sharing octahedra
4.FL.05. Meixnerite group
Meixnerite [Mg6Al2(OH)16][(OH)2 · 4 H2O] trig., R-3m FOTOIMA 1974-003
Fougèrite [Fe2+6Fe3+2(OH)16][(OH)2 · 4 H2O] trig., R-3m IMA 2003-057
Iowaite [Mg6Fe2(OH)16][Cl2 · 4 H2O] trig., R-3m IMA 1967-002
Droninoite [Ni6Fe2(OH)8][Cl2 · 4 H2O] trig., R-3m (?) IMA 2008-003
Woodallite [Mg6Cr2(OH)16][Cl2 · 4 H2O] trig., R-3m IMA 2000-042
Jamborite Ni2+1-xNi3+x(OH)2(OH,S0.5) · n H2O (?) hex. IMA 1971-037
Muskoxite Mg7Fe4(OH)26 · H2O (?) trig., R-3m IMA 1967-043
Akdalaite (Al2O3)4-5 · H2O hex., P63mc IMA 1969-002

Note: This group contains minerals with different structures. Meixnerite, fougèrite, iowaite, droninoite, and woodallite are LDH's (layered double hydroxides) with hydrotalcite structure. The Me2+ : Me3+ ratio is not so fixed as indicated by the formulas above. According to the variability in the composition, the formulas should be better given as [Me2+1-xMe3+x(OH)2][(Aniony-)x/y · n H2O]
Jamborite has probably a hydrotalcite-like structure, but the composition needs further study.
The structure of muskoxite is unknown. Powder diffraction data indicate a relation to the brucite cell. Possibly, muskoxite is a mixed-layer minerals related to coalingite.
Akdalaite has a layer structure, but not related to the LDH minerals and should be better placed in a separate group. IMA 2004-051 ("tohdite", discredited) was found to be identical with the earlier described akdalaite.

4.FL.10. Hydrocalumite group
Hydrocalumite [Ca4Al2(OH)12][(Cl,CO3,OH)2-x · 4 H2O] mon., P2/c G

4.FL.15. Kuzelite group
Kuzelite [Ca4Al2(OH)12][(SO4) · 6 H2O] trig., R-3 or R3 FOTOIMA 1996-053

4.FL.20. Chalcophanite group
Chalcophanite ZnMn4+3O7 · 3 H2O trig., R-3 G
Ernienickelite NiMn4+3O7 · 3 H2O trig., R-3 or R3 FOTOIMA 1993-002
Aurorite (Mn2+,Ag,Ca)Mn4+3O7 · 3 H2O trig., R-3 or R3 IMA 1966-031
Jianshuiite MgMn4+3O7 · 3 H2O tric., P-1 IMA 1990-019

4.FL.25. Woodruffite group
Woodruffite Zn2Mn5O12 · 4 H2O trig., R-3 G

4.FL.30. Asbolane group
Asbolane MnO2 · (Co,Ni,Mg,Ca)x(OH)2x · n H2O hex., P-3m1 FOTOG

4.FL.35. Buserite group
Buserite Na4Mn14O27 · 21 H2O (?) orth. N (?)

4.FL.40. Takanelite group
Takanelite (Mn2+,Ca)2xMn4+1-xO2 · 0.7 H2O hex. FOTOIMA 1970-034
Ranciéite (Ca,Mn2+)0.2(Mn4+,Mn3+)O2 · 0.6 H2O hex. FOTOG

4.FL.45. Birnessite group
Birnessite (Na,Ca,K)0.6(Mn4+,Mn3+)2O4 · 1.5 H2O mon., C2/m FOTOG

4.FL.50. Chenxianite group
Chenxianite AlMn11O16(OH)9 trig. N

4.FL.55. Cianciulliite group
Cianciulliite Mn(Mg,Mn)2Zn2(OH)10 · 2 - 4 H2O mon., C2/m IMA 1990-042

4.FL.60. Jensenite group
Jensenite Cu3TeO6 · 2 H2O mon., P21/n FOTOIMA 1994-043

4.FL.65. Leisingite group
Leisingite (Cu,Mg,Zn)2(Mg,Fe)TeO6 · 6 H2O trig., P-31m FOTOIMA 1995-011

4.FL.70. group deleted

4.FL.75. Cafetite group
Cafetite CaTi2O5 · H2O orth. A

4.FL.80. Mourite group
Mourite UO2Mo5O16 · 5 H2O mon., P2/a or Pa A

4.FL.85. Deloryite group
Deloryite Cu4UO2Mo2O8(OH)6 mon., C2/m IMA 1990-037

4.FM. Hydroxides with H2O +/- (OH); unclassified octahedra
4.FM.05. group deleted

4.FM.10. Sardignaite group *
Gelosaite * BiMo2+xO7(OH) · H2O mon., P21/m IMA 2009-022
Sardignaite * BiMo2O7(OH) · 2 H2O mon., P21/m IMA 2008-040

4.FM.15. Franconite group
Franconite Na2Nb4O11 · 9 H2O mon. IMA 1981-006
Hochelagaite (Ca,Na,Sr)Nb4O11 · 8 H2O mon. IMA 1983-088
Ternovite (Mg,Ca)Nb4O11 · 8 - 12 H2O mon., P2 or Pm IMA 1992-044

4.FM.20. group deleted

4.FM.25. Belyankinite group
Belyankinite Ca1 - 2(Ti,Zr,Nb)5O12 · 9 H2O (?) (?) FOTOQ
Manganbelyankinite (Mn,Ca)(Ti,Nb)5O12 · 9 H2O (?) amorphous Q
Gerasimovskite (Mn,Ca)(Nb,Ti)5O12 · 9 H2O amorphous G

4.FM.30. Silhydrite group
Silhydrite Si3O6 · H2O orth. IMA 1970-044

4.FM.35. Cuzticite group
Cuzticite Fe2TeO6 · 9 H2O hex. IMA 1980-071

4.FM.40. Cyanophyllite group
Cyanophyllite Cu5Al2Sb3O12(OH) · 12 H2O orth., Pmmb IMA 1980-065

4.FN. Oxides/Hydroxides with heteropolyanions
4.FM.05. Menezesite group
Menezesite Ba2MgZr4(BaNb12O42) · 12 H2O cub., Im3 IMA 2005-023

in bold: grandfathered, IMA accepted, renamed and redefined (with IMA approval) minerals,
in normal letters: minerals published without IMA approval, questionable minerals, polytypes

G = Grandfathered minerals: original description preceded the establishment of the CNMNC in 1959, and generally regarded as a valid species
A or IMA No. = Minerals approved by the CNMNC
Rd = Redefinition of the mineral approved by the CNMNC
Rn = Renamed with approval by the CNMNC
GROUP = a name used to designate a group of species
N = Mineral published without approval of the CNMNC
Q = Questionable mineral
H = Hypothetical mineral (synthetic, anthropogenic, etc.)
D = Discredited by the CNMNC
Poly = Polytype

© Thomas Witzke / Stollentroll (2007 - 2009)