Coombsite
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About Coombsite
Formula:
K(Mn,Fe,Mg)13(Si,Al)18O42(OH)14
Colour:
Pale brownish yellow
Crystal System:
Trigonal
Name:
Named in 1991 by Teruhiko Sameshima and Yosuke Kawachi in honor of Douglas S. Coombs, professor of geology at the University of Otago, New Zealand. Coombs first described progressive mineralogical changes, especially relating to zeolites, due to low grade burial metamorphism. Coombs named wairakite, ferroceladonite, and ferroaluminoceladonite.
Isostructural with:
Classification of Coombsite
Approved
8/H.40-20
9.EG.35
9 : SILICATES (Germanates)
E : Phyllosilicates
G : Double nets with 6-membered and larger rings
9 : SILICATES (Germanates)
E : Phyllosilicates
G : Double nets with 6-membered and larger rings
16.16.18
16 : Silicates Containing Aluminum and other Metals
16 : Aluminosilicates of Mn
16 : Silicates Containing Aluminum and other Metals
16 : Aluminosilicates of Mn
Physical Properties of Coombsite
Colour:
Pale brownish yellow
Optical Data of Coombsite
Type:
Uniaxial (-)
RI values:
nω = 1.619 nε = 1.600
Max Birefringence:
δ = 0.019

Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Moderate
Chemical Properties of Coombsite
Formula:
K(Mn,Fe,Mg)13(Si,Al)18O42(OH)14
IMA Formula:
KMn2+13(Si,Al)18O42(OH)14
Common Impurities:
Ti,Ca,Na
Crystallography of Coombsite
Crystal System:
Trigonal
Cell Parameters:
a = 11.82 Å, c = 29.14 Å
Ratio:
a:c = 1 : 2.465
Unit Cell V:
3,525.78 ų (Calculated from Unit Cell)
Type Occurrence of Coombsite
General Appearance of Type Material:
Aggregates of fibro-lamellar crystals up
to 20 micron in length, and often shows semispherulitic texture.
to 20 micron in length, and often shows semispherulitic texture.
Geological Setting of Type Material:
A 50 cm thick rhodonite-quartz lens.
Associated Minerals at Type Locality:
Synonyms of Coombsite
Other Language Names for Coombsite
Common Associates
Associated Minerals Based on Photo Data:
Related Minerals - Nickel-Strunz Grouping
9.EG.05 | Cymrite | BaAl2Si2(O,OH)8 · H2O | Mon. |
9.EG.10 | Naujakasite | (Na,K)6(Fe2+,Mn2+,Ca)(Al,Fe)4Si8O26 | Mon. 2/m : B2/m |
9.EG.10 | Manganonaujakasite | Na6(Mn2+,Fe2+)Al4Si8O26 | Mon. |
9.EG.15 | Dmisteinbergite | Ca(Al2Si2O8) | Hex. 6/mmm (6/m 2/m 2/m) : P6/mmm |
9.EG.20 | Kampfite | Ba12(Si11Al5)O31(CO3)8Cl5 | Mon. m |
9.EG.25 | Strätlingite | Ca2Al2SiO7 · 8H2O | Trig. |
9.EG.25 | Vertumnite | Ca4Al4Si4O6(OH)24 · 3H2O | Mon. 2/m : P21/m |
9.EG.30 | Eggletonite | (Na,K,Ca)2(Mn,Fe)8(Si,Al)12O29(OH)7 · 11H2O | Mon. |
9.EG.30 | Ganophyllite | (K,Na,Ca)2Mn8(Si,Al)12(O,OH)32 · 8H2O | Mon. |
9.EG.30 | Tamaite | (Ca,K,Ba,Na)3-4Mn24(Si,Al)40(O,OH)112 · 21H2O | Mon. |
9.EG.35 | Zussmanite | K(Fe,Mg,Mn)13(Si,Al)18O42(OH)14 | Trig. 3 : R3 |
9.EG.40 | Franklinphilite | (K,Na)4(Mn2+,Mg,Zn)48(Si,Al)72(O,OH)216 · 6H2O | Tric. |
9.EG.40 | Lennilenapeite | K6-7(Mg,Mn,Fe,Zn)48(Si,Al)72(O,OH)216 · 16H2O | Tric. |
9.EG.40 | Parsettensite | (K,Na,Ca)7.5(Mn,Mg)49Si72O168(OH)50 · nH2O | Mon. 2/m : B2/m |
9.EG.40 | Stilpnomelane | (K,Ca,Na)(Fe2+,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O | Tric. 1 : P1 |
9.EG.45 | Latiumite | (Ca,K)4(Si,Al)5O11(SO4,CO3) | Mon. |
9.EG.45 | Tuscanite | (K(Ca,Na)6(Si,Al)10O22[SO4,CO3,(OH)2] · H2O | Mon. |
9.EG.50 | Jagoite | Pb18Fe3+4[Si4(Si,Fe3+)6][Pb4Si16(Si,Fe)4]O82Cl6 | Hex. |
9.EG.55 | Wickenburgite | CaPb3Al2Si10O24(OH)6 | Trig. 3m : P3 1c |
9.EG.60 | Hyttsjöite | Pb18Ba2Ca5Mn2+2Fe3+2Si30O90Cl · 6H2O | Trig. |
9.EG.65 | Armbrusterite | K5Na7Mn15[(Si9O22)4](OH)10 · 4H2O | Mon. 2/m : B2/m |
9.EG.70 | Britvinite | [Pb7(OH)3F(BO3)2(CO3)][Mg4.5(OH)3(Si5O14)] | Tric. 1 : P1 |
9.EG.75 | Bannisterite | (Ca,K,Na)(Mn2+,Fe2+)10(Si,Al)16O38(OH)8 · nH2O | Mon. 2/m : B2/b |
Related Minerals - Hey's Chemical Index of Minerals Grouping
16.16.1 | Kanonaite | Mn3+Al(SiO4)O | Orth. mmm (2/m 2/m 2/m) : Pnnm |
16.16.2 | Spessartine | Mn2+3Al2(SiO4)3 | Iso. m3m (4/m 3 2/m) : Ia3d |
16.16.3 | Davreuxite | MnAl6Si4O17(OH)2 | Mon. |
16.16.4 | Sursassite | Mn2+2Al3(SiO4)(Si2O7)(OH)3 | Mon. 2/m : P21/m |
16.16.5 | Carpholite | Mn2+Al2(Si2O6)(OH)4 | Orth. |
16.16.6 | Kellyite | Mn2+2Al(AlSiO5)(OH)4 | Hex. |
16.16.7 | Pennantite | Mn2+5Al(AlSi3O10)(OH)8 | Tric. |
16.16.8 | Akatoreite | Mn2+9Al2Si8O24(OH)8 | Tric. |
16.16.9 | Ganophyllite | (K,Na,Ca)2Mn8(Si,Al)12(O,OH)32 · 8H2O | Mon. |
16.16.10 | Mangano-ferri-eckermannite | {Na}{Na2}{Mn2+4Fe3+}Si8O22(OH)2 | Mon. |
16.16.11 | Masutomilite | (K,Rb)(Li,Mn3+,Al)3(AlSi3O10)(F,OH)2 | Mon. |
16.16.13 | Howieite | Na(Fe,Mn)10(Fe,Al)2Si12O31(OH)13 | Tric. |
16.16.14 | Eggletonite | (Na,K,Ca)2(Mn,Fe)8(Si,Al)12O29(OH)7 · 11H2O | Mon. |
16.16.15 | Bannisterite | (Ca,K,Na)(Mn2+,Fe2+)10(Si,Al)16O38(OH)8 · nH2O | Mon. 2/m : B2/b |
16.16.16 | Taneyamalite | (Na,Ca)(Mn,Mg,Fe)12Si12(O,OH)44 | Tric. |
16.16.17 | Zussmanite | K(Fe,Mg,Mn)13(Si,Al)18O42(OH)14 | Trig. 3 : R3 |
16.16.19 | Henritermierite | Ca3(Mn3+,Al)2(SiO4)2(OH)4 | Tet. 4/mmm (4/m 2/m 2/m) : I41/acd |
16.16.20 | Macfallite | Ca2Mn3+3(SiO4)(Si2O7)(OH)3 | Mon. |
16.16.21 | Ottrélite | (Mn2+,Fe2+,Mg)Al2(SiO4)O(OH)2 | Mon. |
16.16.22 | Piemontite | {Ca2}{Al2Mn3+}(Si2O7)(SiO4)O(OH) | Mon. 2/m : P21/m |
16.16.23 | Okhotskite | Ca2(Mn,Mg)(Mn3+,Al,Fe3+)2(Si2O7)(SiO4)(OH)2 · H2O | Mon. |
16.16.24 | Pumpellyite-(Mn2+) | Ca2Mn2+Al2(Si2O7)(SiO4)(OH)2 · H2O | Mon. |
16.16.25 | Piemontite-(Sr) | {CaSr}{Al2Mn3+}(Si2O7)(SiO4)O(OH) | Mon. |
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
References for Coombsite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
New Minerals (1997), New Minerals 1990-1994.
Sameshima, T. and Kawachi, Y. (1991): Coombsite, manganese analogue of zussmanite, and associated Mn-silicates, parsettensite and caryopilite, from southeast Otago, New Zealand Journal of Geology and Geophysics: 34, 329-335.
Internet Links for Coombsite
mindat.org URL:
https://www.mindat.org/min-1122.html
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Localities for Coombsite
Locality List




All localities listed without proper references should be considered as questionable.
Brazil | |
| Farber Minerals |
New Zealand (TL) | |
| Sameshima, T., Kawachi, Y. (1991) Coombsite, Mn analogue of zussmanite, and associated Mn-silicates, parsettensite and caryopilite, from southeast Otago, New Zealand. New Zealand Journal of Geology and Geophysics, 34:3, 329-335. |
Romania | |
| http://minerals-of-the-carpathians.eu |
Watsons Beach, Clutha District, Otago Region, South Island, New Zealand