Keckite
A valid IMA mineral species
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About Keckite
Formula:
CaMn2+(Fe3+Mn2+)Fe3+2(PO4)4(OH)3 · 7H2O
Colour:
Golden brown, orange brown
Lustre:
Sub-Vitreous, Resinous
Hardness:
4½
Specific Gravity:
2.6
Crystal System:
Monoclinic
Member of:
Name:
Named by Arno Mücke in 1979 in honor of Erich Keck (b. 1938) of Germany, mineral collector specializing in Hagendorf minerals. His large collection of Hagendorf minerals is now preserved at Mineralogische Staatssammlung, Munich, Germany.
A member of the jahnsite group which contains trivalent iron not only at the C site but also at the B site.
Note: According to Hochleitner & Fehr (2010), keckite from Hagendorf forms golden-yellow to orange fibrous crusts which are intimately associated with rockbridgeite-frondelite. Specimens showing distinct "keckite" crystals in collections were found to be always either jahnsite-(CaMnFe) or jahnsite-(CaMnMn).
Compare Jahnsite-(CaMnFe).
Possibly intermediate between Jahnsite-(CaMnMn) and Jahnsite-(CaMnFe) and not a valid species, requires investigation into valance state and occupancy of the Fe.
Note: According to Hochleitner & Fehr (2010), keckite from Hagendorf forms golden-yellow to orange fibrous crusts which are intimately associated with rockbridgeite-frondelite. Specimens showing distinct "keckite" crystals in collections were found to be always either jahnsite-(CaMnFe) or jahnsite-(CaMnMn).
Compare Jahnsite-(CaMnFe).
Possibly intermediate between Jahnsite-(CaMnMn) and Jahnsite-(CaMnFe) and not a valid species, requires investigation into valance state and occupancy of the Fe.
Unique Identifiers
Mindat ID:
2174
Long-form identifier:
mindat:1:1:2174:2
GUID
(UUID V4):
(UUID V4):
8a72b7c0-dd22-4531-9530-0c6abe4e6e50
IMA Classification of Keckite
Approved
IMA Formula:
CaMn(Fe3+,Mn)2Fe3+2(PO4)4(OH)3 · 7H2O
Approval year:
1977
First published:
1979
Classification of Keckite
8.DH.15
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
H : With large and medium-sized cations, (OH, etc.):RO4 < 1:1
8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
H : With large and medium-sized cations, (OH, etc.):RO4 < 1:1
42.11.4.1
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
11 : (AB)3(XO4)2Zq·xH2O
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
11 : (AB)3(XO4)2Zq·xH2O
19.12.44
19 : Phosphates
12 : Phosphates of Mn
19 : Phosphates
12 : Phosphates of Mn
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Symbol | Source | Reference |
---|---|---|
Kec | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Pronunciation of Keckite
Pronunciation:
Play | Recorded by | Country |
---|---|---|
Jolyon Ralph | United Kingdom |
Physical Properties of Keckite
Sub-Vitreous, Resinous
Transparency:
Transparent, Translucent
Colour:
Golden brown, orange brown
Comment:
Possibly sore are red brown, but these tend to be other jahnsites.
Streak:
Yellow brown
Hardness:
4½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Distinct/Good
{001}, {100}
{001}, {100}
Fracture:
Irregular/Uneven, Splintery
Density:
2.6 g/cm3 (Measured) 2.682 g/cm3 (Calculated)
Comment:
Also D= 2.649
Optical Data of Keckite
Type:
Biaxial (-)
Dispersion:
weak to distinct
Optical Extinction:
X ^ c = 15-20 degrees
Pleochroism:
Strong
Comments:
X reddish brown, Y yellow, Z bright yellow
Comments:
Undulatory extinction; Birefringence probably similar to other jahnsites
Chemistry of Keckite
Mindat Formula:
CaMn2+(Fe3+Mn2+)Fe3+2(PO4)4(OH)3 · 7H2O
Common Impurities:
Mg
Crystallography of Keckite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P2/b
Setting:
P2/a
Cell Parameters:
a = 15.02 Å, b = 7.19 Å, c = 19.74 Å
β = 110.5°
β = 110.5°
Ratio:
a:b:c = 2.089 : 1 : 2.745
Unit Cell V:
1,996.80 ų (Calculated from Unit Cell)
Morphology:
Tightly clustered bladed to stout crystals arranged in subparallel groups.
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
9.3 Å | (80) |
4.98 Å | (50) |
4.63 Å | (30) |
3.51 Å | (50) |
2.86 Å | (100) |
2.59 Å | (40) |
2.34 Å | (30) |
1.879 Å | (40) |
Comments:
ICDD 33-289
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 7: Great Oxidation Event | <2.4 |
47a : [Near-surface hydration of prior minerals] | |
47c : [Carbonates, phosphates, borates, nitrates] |
Type Occurrence of Keckite
General Appearance of Type Material:
Crusts of yellow-brown to golden brown indistinct crystals.
Geological Setting of Type Material:
Late stage oxidized mineralization in secondary phosphate-rich granite pegmatites.
Associated Minerals at Type Locality:
Reference:
Mücke, A. (1979) Keckit, (Ca,Mg)(Mn,Zn)2Fe3+3[(OH)3|(PO4)4]·2H2O, ein neues Mineral von Hagendorf/Opf. und seine genetische Stellung. Neues Jahrbuch für Mineralogie, Abhandlungen: 134: 183-192.
Synonyms of Keckite
Other Language Names for Keckite
Relationship of Keckite to other Species
Member of:
Other Members of this group:
Jahnsite-(CaFeFe) | {Ca}{Fe2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. |
Jahnsite-(CaFeMg) | CaFe2+Mg2Fe3+2(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
Jahnsite-(CaMnFe) | {Ca}{Mn2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
Jahnsite-(CaMnMg) | {Ca}{Mn2+}{(Mg,Fe2+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
Jahnsite-(CaMnMn) | {Ca}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
Jahnsite-(CaMnZn) | CaMn2+Zn2Fe3+2(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
Jahnsite-(MnMnFe) | Mn2+Mn2+Fe2+2Fe3+2(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
Jahnsite-(MnMnMg) | Mn2+Mn2+Mg2Fe3+2(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
Jahnsite-(MnMnMn) | {Mn2+}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P21/b |
Jahnsite-(MnMnZn) | Mn2+Mn2+Zn2Fe3+2(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
Jahnsite-(NaFeMg) | NaFe3+Mg2Fe3+2(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
Jahnsite-(NaMnMg) | {(Na,Ca)}{(Mn2+,Fe3+)}{(Mg,Fe3+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
Jahnsite-(NaMnMn) | NaMn2+(Mn2+Fe3+)Σ2Fe3+2(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
Common Associates
Associated Minerals Based on Photo Data:
5 photos of Keckite associated with Strengite | FePO4 · 2H2O |
5 photos of Keckite associated with Rockbridgeite | Fe2+Fe3+4(PO4)3(OH)5 |
4 photos of Keckite associated with Phosphophyllite | Zn2Fe(PO4)2 · 4H2O |
4 photos of Keckite associated with Strunzite | Mn2+Fe3+2(PO4)2(OH)2 · 6H2O |
3 photos of Keckite associated with Kingsmountite | Ca3MnFeAl4(PO4)6(OH)4 · 12H2O |
3 photos of Keckite associated with Scholzite | CaZn2(PO4)2 · 2H2O |
2 photos of Keckite associated with Cryptomelane | K(Mn4+7Mn3+)O16 |
1 photo of Keckite associated with Schoonerite | ZnMn2+Fe2+2Fe3+(PO4)3(OH)2 · 9H2O |
1 photo of Keckite associated with Phosphosiderite | FePO4 · 2H2O |
1 photo of Keckite associated with Beraunite | Fe3+6(PO4)4O(OH)4 · 6H2O |
Related Minerals - Strunz-mindat Grouping
8.DH. | Ferroberaunite | Fe2+Fe3+5(PO4)4(OH)5 · 6H2O |
8.DH. | Rowleyite | [Na(NH4,K)9Cl4][V5+,4+2(P,As)O8]6 · n[H2O,Na,NH4,K,Cl] |
8.DH. | Ammoniotinsleyite | (NH4)Al2(PO4)2(OH) · 2H2O |
8.DH. | Thebaite-(NH4) | (NH4)3Al(C2O4)(PO3OH)2(H2O) |
8.DH. | Dendoraite-(NH4) | (NH4)2NaAl(C2O4)(PO3OH)2(H2O)2 |
8.DH. | Whiteite-(MnMnMn) | Mn2+Mn2+Mn2+2Al2(PO4)4(OH)2 · 8H2O |
8.DH. | Whiteite-(CaMnFe) | CaMnFe2Al2(PO4)4(OH)2 · 8H2O |
8.DH. | Hochleitnerite | Mn2Ti3(PO4)4O2(H2O)2 · 14H2O |
8.DH. | Regerite | KFe6(PO4)4(OH)7(H2O)6 · 4H2O |
8.DH.05 | Minyulite | KAl2(PO4)2F · 4H2O |
8.DH.10 | Leucophosphite | KFe3+2(PO4)2(OH) · 2H2O |
8.DH.10 | Spheniscidite | (NH4,K)(Fe3+,Al)2(PO4)2(OH) · 2H2O |
8.DH.10 | Tinsleyite | KAl2(PO4)2(OH) · 2H2O |
8.DH.15 | Jahnsite-(CaMnFe) | {Ca}{Mn2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(CaMnMg) | {Ca}{Mn2+}{(Mg,Fe2+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(CaMnMn) | {Ca}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Rittmannite | {(Mn2+,Ca)}{Mn2+}{(Fe2+,Mn2+,Mg)2}{(Al,Fe3+)2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Whiteite-(CaFeMg) | {Ca}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Whiteite-(CaMnMg) | {Ca}{Mn2+}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Whiteite-(MnFeMg) | {(Mn2+,Ca)}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(MnMnMn) | {Mn2+}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Kaluginite | (Mn2+,Ca)MgFe3+(PO4)2(OH) · 4H2O |
8.DH.15 | Jahnsite-(CaFeFe) | {Ca}{Fe2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(NaFeMg) | NaFe3+Mg2Fe3+2(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(NaMnMg) | {(Na,Ca)}{(Mn2+,Fe3+)}{(Mg,Fe3+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(CaMgMg) | {Ca}{Mg}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Whiteite-(CaMnMn) | {Ca}{Mn2+}{Mn2}{Al2}(PO4)4(OH)2 · 8H2O |
8.DH.15 | Whiteite-(MnMnMg) | MnMnMg2Al2(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(MnMnMg) | Mn2+Mn2+Mg2Fe3+2(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(CaFeMg) | CaFe2+Mg2Fe3+2(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(MnMnFe) | Mn2+Mn2+Fe2+2Fe3+2(PO4)4(OH)2 · 8H2O |
8.DH.15 | Whiteite-(CaMgMg) | CaMg3Al2(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(MnMnZn) | Mn2+Mn2+Zn2Fe3+2(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(NaMnMn) | NaMn2+(Mn2+Fe3+)Σ2Fe3+2(PO4)4(OH)2 · 8H2O |
8.DH.15 | Jahnsite-(CaMnZn) | CaMn2+Zn2Fe3+2(PO4)4(OH)2 · 8H2O |
8.DH.20 | Lun'okite | (Mn,Ca)(Mg,Fe,Mn)Al(PO4)2OH · 4H2O |
8.DH.20 | Manganosegelerite | (Mn2+,Ca)(Mn2+,Fe2+,Mg)Fe3+(PO4)2(OH) · 4H2O |
8.DH.20 | Overite | CaMgAl(PO4)2(OH) · 4H2O |
8.DH.20 | Segelerite | Ca2 Mg2 Fe3+2(PO4)4(OH)2 · 8H2O |
8.DH.20 | Wilhelmvierlingite | CaMnFe3+(PO4)2(OH) · 2H2O |
8.DH.20 | Juonniite | CaMgSc(PO4)2(OH) · 4H2O |
8.DH.25 | Calcioferrite | Ca2Fe3+2(PO4)3(OH) · 7H2O |
8.DH.25 | Kingsmountite | Ca3MnFeAl4(PO4)6(OH)4 · 12H2O |
8.DH.25 | Montgomeryite | Ca4MgAl4(PO4)6(OH)4 · 12H2O |
8.DH.25 | Zodacite | Ca4Mn2+Fe3+4(PO4)6(OH)4 · 12H2O |
8.DH.25 | Fanfaniite | Ca4MnAl4(PO4)6(OH)4 · 12H2O |
8.DH.30 | Arseniosiderite | Ca2Fe3+3(AsO4)3O2 · 3H2O |
8.DH.30 | Kolfanite | Ca2Fe3+3O2(AsO4)3 · 2H2O |
8.DH.30 | Mitridatite | Ca2Fe3+3(PO4)3O2 · 3H2O |
8.DH.30 | Pararobertsite | Ca2Mn3+3(PO4)3O2 · 3H2O |
8.DH.30 | Robertsite | Ca2Mn3+3(PO4)3O2 · 3H2O |
8.DH.30 | Sailaufite | (Ca,Na,◻)2Mn3+3(AsO4)2(CO3)O2 · 3H2O |
8.DH.35 | Mantienneite | KMg2Al2Ti(PO4)4(OH)3 · 15H2O |
8.DH.35 | Paulkerrite | K(Mg,Mn2+)2(Fe3+,Al,Ti,Mg)2Ti(PO4)4(OH)3 · 15H2O |
8.DH.35 | Benyacarite | (H2O)2Mn2Ti2Fe3+(PO4)4(OF)(H2O)10 · 4H2O |
8.DH.35 | Hydroxylbenyacarite | (H2O)2Mn2(Ti2Fe)(PO4)4[O(OH)](H2O)10 · 4H2O |
8.DH.35 | Macraeite | K(H2O)Mn2(Fe2Ti)(PO4)4[O(OH)](H2O)10 · 4H2O |
8.DH.40 | Xanthoxenite | Ca4Fe3+2(PO4)4(OH)2 · 3H2O |
8.DH.45 | Mahnertite | NaCu3(AsO4)2Cl · 5H2O |
8.DH.50 | Andyrobertsite | KCdCu5(AsO4)4(H2AsO4) · 2H2O |
8.DH.50 | Calcioandyrobertsite | KCaCu5(AsO4)4(H2AsO4) · 2H2O |
8.DH.55 | Englishite | K3Na2Ca10Al15(PO4)21(OH)7 · 26H2O |
8.DH.60 | Bouazzerite | Bi6(Mg,Co)11Fe3+14(AsO4)18(OH)4O12 · 86H2O |
8.DH.65 | Galliskiite | Ca4Al2(PO4)2F8 · 5H2O |
8.DH.70 | Joteite | Ca2CuAl(AsO4)[AsO3(OH)]2(OH)2 · 5H2O |
8.DH.75 | Kampelite | Ba6Mg3Sc8(PO4)12(OH)6 · 7H2O |
8.DH.80 | Kapundaite | NaCaFe4(PO4)4(OH)3 · 5H2O |
8.DH.85 | Vaniniite | Ca2Mn2+3Mn3+2O2(AsO4)4 · 2H2O |
Fluorescence of Keckite
Not fluorescent
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.
Internet Links for Keckite
mindat.org URL:
https://www.mindat.org/min-2174.html
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References for Keckite
Reference List:
Fleischer, Michael, Burns, Roger G., Cabri, Louis J., Chao, George Y., Hogarth, D. D., Pabst, Adolf (1979) New Mineral Names. American Mineralogist, 64 (11-12) 1329-1334
Localities for Keckite
Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
Struck out - Mineral was erroneously reported from this locality.
Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).
All localities listed without proper references should be considered as questionable.
All localities listed without proper references should be considered as questionable.
Australia | |
| Dr. Bill Birch - Museum Victoria |
DR Congo | |
| Mills et al. (2010) |
Germany | |
| Weiß (1990) |
| Dill et al. (2008) |
| Dill (2009) |
Neues Jahrb.Min. (1979) +2 other references | |
| Wittern (2001) +1 other reference |
Portugal | |
| |
| Schnorrer-Köhler (1991) |
Spain | |
| www.foro-minerales.com (n.d.) |
USA | |
| Whitmore et al. (2004) +2 other references |
Quick NavTopAbout KeckiteUnique IdentifiersIMA Classification Classification Mineral SymbolsPronunciation Physical Properties Optical Data Chemistry Crystallography X-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesRelationshipsCommon AssociatesStrunz-MindatFluorescence Other InformationInternet Links References Localities Locality List
Hagendorf South Pegmatite, Hagendorf, Waidhaus, Neustadt an der Waldnaab District, Upper Palatinate, Bavaria, Germany