Pararobertsite
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About Pararobertsite
Formula:
Ca2Mn3+3(PO4)3O2 · 3H2O
Colour:
Bronze, cinnamon brown, yellow, dark red
Lustre:
Sub-Vitreous, Resinous, Waxy, Greasy
Hardness:
2
Specific Gravity:
3.22
Crystal System:
Monoclinic
Name:
Named in 1988 by Andrew C. Roberts, B. Darko Sturman, Pete J. Dunn, and Willard L. Roberts, from the Greek 'para' for near, and robertsite, for the polymorphic relationship with that mineral.
Type Locality:
Dimorph of:
This page provides mineralogical data about Pararobertsite.
Classification of Pararobertsite
Approved
Approval Year:
1987
First Published:
1989
7/D.30-60
8.DH.30
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
Dana 7th ed.:
42.8.5.2
42.8.5.2
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
8 : (AB)5(XO4)3Zq·xH2O
42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
8 : (AB)5(XO4)3Zq·xH2O
19.12.7
19 : Phosphates
12 : Phosphates of Mn
19 : Phosphates
12 : Phosphates of Mn
Physical Properties of Pararobertsite
Sub-Vitreous, Resinous, Waxy, Greasy
Transparency:
Transparent, Translucent
Colour:
Bronze, cinnamon brown, yellow, dark red
Comment:
Usually dark red to cinnamon brown
Streak:
Brown-red
Hardness:
2 on Mohs scale
Tenacity:
Brittle
Cleavage:
Perfect
on {100}
on {100}
Fracture:
Irregular/Uneven
Density:
3.22 g/cm3 (Measured) 3.21 g/cm3 (Calculated)
Optical Data of Pararobertsite
Type:
Biaxial (-)
RI values:
nα = 1.791 nβ = 1.811 nγ = 1.831
2V:
Measured: 84° , Calculated: 85° to 88°
Birefringence:
0.040
Max Birefringence:
δ = 0.040

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:
Very High
Dispersion:
extreme
Optical Extinction:
Z^c = 4°
Pleochroism:
Weak
Comments:
X=yellowish brown; Y=Z=reddish brown; Z=Y>X
Chemical Properties of Pararobertsite
Formula:
Ca2Mn3+3(PO4)3O2 · 3H2O
Crystallography of Pararobertsite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P21/b
Setting:
P21/c
Cell Parameters:
a = 8.825 Å, b = 13.258 Å, c = 11.087 Å
β = 101.19°
β = 101.19°
Ratio:
a:b:c = 0.666 : 1 : 0.836
Unit Cell V:
1272.54 ų
Z:
4
Morphology:
Triangular to pseudo-rhombohedral plates, sometimes rhombic plates.
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
8.69 | (100) |
5.66 | (60) |
5.44 | (50) |
2.884 | (60) |
2.772 | (70) |
2.611 | (60) |
2.163 | (60) |
Type Occurrence of Pararobertsite
Reference:
Roberts, Andrew C., Sturman, B. Darko, Dunn, P. J., and Roberts, Willard, L. (1989) Pararobertsite, Ca2 Mn3+3 (PO4 )3 )2 .3H2 ), a New Mineral Species from the Tip Top Pegmatite, Custer County, South Dakota, and its Relationship to Robertsite. Canadian Mineralogist: 27: 451-455.
Synonyms of Pararobertsite
Other Language Names for Pararobertsite
Relationship of Pararobertsite to other Species
Structurally related to group(s):
Common Associates
Associated Minerals Based on Photo Data:
Bobdownsite | 7 photos of Pararobertsite associated with Bobdownsite on mindat.org. |
Whitlockite | 2 photos of Pararobertsite associated with Whitlockite on mindat.org. |
Related Minerals - Nickel-Strunz Grouping
8.DH.05 | Minyulite | KAl2(PO4)2(OH,F) · 4H2O | Orth. mm2 : Pba2 |
8.DH.10 | Leucophosphite | KFe3+2(PO4)2(OH) · 2H2O | Mon. 2/m : P21/b |
8.DH.10 | Spheniscidite | (NH4,K)(Fe3+,Al)2(PO4)2(OH) · 2H2O | Mon. |
8.DH.10 | Tinsleyite | KAl2(PO4)2(OH) · 2H2O | Mon. |
8.DH.15 | Jahnsite-(CaMnFe) | {Ca}{Mn2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
8.DH.15 | Jahnsite-(CaMnMg) | {Ca}{Mn2+}{(Mg,Fe2+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
8.DH.15 | Jahnsite-(CaMnMn) | {Ca}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
8.DH.15 | Keckite | CaMn2+(Fe3+Mn2+)Fe3+2(PO4)4(OH)3 · 7H2O | Mon. 2/m : P2/b |
8.DH.15 | Rittmannite | {(Mn2+,Ca)}{Mn2+}{(Fe2+,Mn2+,Mg)2}{(Al,Fe3+)2}(PO4)4(OH)2 · 8H2O | Mon. |
8.DH.15 | Whiteite-(CaFeMg) | {Ca}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P21/b |
8.DH.15 | Whiteite-(CaMnMg) | {Ca}{Mn2+}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O | Mon. 2/m |
8.DH.15 | Whiteite-(MnFeMg) | {(Mn2+,Ca)}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P21/b |
8.DH.15 | Jahnsite-(MnMnMn) | {Mn2+}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. |
8.DH.15 | Kaluginite | (Mn2+,Ca)MgFe3+(PO4)2(OH) · 4H2O | Orth. |
8.DH.15 | Jahnsite-(CaFeFe) | {Ca}{Fe2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. |
8.DH.15 | Jahnsite-(NaFeMg) | NaFe3+Mg2Fe3+2(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
8.DH.15 | Jahnsite-(NaMnMg) | {(Na,Ca)}{(Mn2+,Fe3+)}{(Mg,Fe3+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
8.DH.15 | Jahnsite-(CaMgMg) | {Ca}{Mg}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O | |
8.DH.20 | Manganosegelerite | (Mn2+,Ca)(Mn2+,Fe2+,Mg)Fe3+(PO4)2(OH) · 4H2O | Orth. mmm (2/m 2/m 2/m) : Pbca |
8.DH.20 | Overite | CaMgAl(PO4)2(OH) · 4H2O | Orth. mmm (2/m 2/m 2/m) : Pbca |
8.DH.20 | Segelerite | Ca2 Mg2 Fe3+2(PO4)4(OH)2 · 8H2O | Orth. mmm (2/m 2/m 2/m) : Pcca |
8.DH.20 | Wilhelmvierlingite | CaMnFe3+(PO4)2(OH) · 2H2O | Orth. |
8.DH.20 | Juonniite | CaMgSc(PO4)2(OH) · 4H2O | Orth. |
8.DH.25 | Calcioferrite | Ca2Fe3+2(PO4)3(OH) · 7H2O | Mon. 2/m : B2/b |
8.DH.25 | Kingsmountite | Ca4(Fe2+,Mn2+)Al4(PO4)6(OH)4 · 12H2O | Mon. 2 : B2 |
8.DH.25 | Montgomeryite | Ca4MgAl4(PO4)6(OH)4 · 12H2O | Mon. 2 : B2 |
8.DH.25 | Zodacite | Ca4Mn2+Fe3+4(PO4)6(OH)4 · 12H2O | Mon. |
8.DH.30 | Arseniosiderite | Ca2Fe3+3(AsO4)3O2 · 3H2O | Mon. 2/m : B2/b |
8.DH.30 | Kolfanite | Ca2Fe3+3O2(AsO4)3 · 2H2O | Mon. |
8.DH.30 | Mitridatite | Ca2Fe3+3(PO4)3O2 · 3H2O | Mon. 2/m : B2/b |
8.DH.30 | Robertsite | Ca2Mn3+3(PO4)3O2 · 3H2O | Mon. m : Bb |
8.DH.30 | Sailaufite | (Ca,Na,☐)2Mn3+3(AsO4)2(CO3)O2 · 3H2O | Mon. |
8.DH.35 | Mantienneite | KMg2Al2Ti(PO4)4(OH)3 · 15H2O | Orth. |
8.DH.35 | Paulkerrite | K(Mg,Mn2+)2(Fe3+,Al,Ti,Mg)2Ti(PO4)4(OH)3 · 15H2O | Orth. mmm (2/m 2/m 2/m) : Pbca |
8.DH.35 | Benyacarite | (H2O,K)2(Mn2+,Fe2+)2(Fe3+,Ti)2Ti(PO4)4(O,F)2 · 14H2O | Orth. mmm (2/m 2/m 2/m) : Pbca |
8.DH.40 | Xanthoxenite | Ca4Fe3+2(PO4)4(OH)2 · 3H2O | Tric. 1 : P1 |
8.DH.45 | Mahnertite | NaCu3(AsO4)2Cl · 5H2O | Tet. 4/mmm (4/m 2/m 2/m) : I4/mmm |
8.DH.50 | Andyrobertsite | KCdCu5(AsO4)4(H2AsO4) · 2H2O | Mon. |
8.DH.50 | Calcioandyrobertsite | KCaCu5(AsO4)4(H2AsO4) · 2H2O | Mon. 2/m : P21/m |
8.DH.55 | Englishite | K3Na2Ca10Al15(PO4)21(OH)7 · 26H2O | Mon. 2/m |
8.DH.60 | Bouazzerite | Bi6(Mg,Co)11Fe3+14(AsO4)18(OH)4O12 · 86H2O | Mon. 2/m |
Related Minerals - Dana Grouping (8th Ed.)
42.8.5.1 | Kolfanite | Ca2Fe3+3O2(AsO4)3 · 2H2O | Mon. |
Related Minerals - Hey's Chemical Index of Minerals Grouping
19.12.1 | Metaswitzerite | Mn2+3(PO4)2 · 4H2O | Mon. 2/m : P2/b |
19.12.2 | Bermanite | Mn2+Mn3+2(PO4)2(OH)2 · 4H2O | Mon. 2/m : P2/b |
19.12.3 | Natrophilite | NaMn2+PO4 | Orth. mmm (2/m 2/m 2/m) : Pmna |
19.12.4 | Sidorenkite | Na3Mn2+(CO3)(PO4) | Mon. |
19.12.5 | Niahite | (NH4)(Mn2+,Mg)(PO4) · H2O | Orth. mm2 : Pmn21 |
19.12.6 | Robertsite | Ca2Mn3+3(PO4)3O2 · 3H2O | Mon. m : Bb |
19.12.8 | Sinkankasite | Mn2+Al(PO3OH)2(OH) · 6H2O | Tric. |
19.12.9 | Mangangordonite | Mn2+Al2(PO4)2(OH)2 · 8H2O | Tric. |
19.12.10 | Heterosite | (Fe3+,Mn3+)PO4 | Orth. mmm (2/m 2/m 2/m) : Pmna |
19.12.11 | Purpurite | (Mn3+,Fe3+)PO4 | Orth. mmm (2/m 2/m 2/m) : Pmna |
19.12.12 | Wolfeite | (Fe2+,Mn2+)2(PO4)(OH) | Mon. 2/m : P21/b |
19.12.13 | Triploidite | (Mn2+,Fe2+)2(PO4)(OH) | Mon. 2/m : P2/b |
19.12.14 | Lipscombite | Fe2+Fe3+2(PO4)2(OH)2 | Tet. |
19.12.15 | Frondelite | Mn2+Fe3+4(PO4)3(OH)5 | Orth. 2 2 2 : C2 2 21 |
19.12.16 | Rockbridgeite | Fe2+Fe3+4(PO4)3(OH)5 | Orth. mmm (2/m 2/m 2/m) |
19.12.17 | Kryzhanovskite | (Fe3+,Mn2+)3(PO4)2(OH,H2O)3 | Orth. |
19.12.18 | Landesite | Mn2+3-xFe3+x(PO4)2(OH)x · (3-x)H2O | Orth. |
19.12.19 | Phosphoferrite | (Fe2+,Mn2+)3(PO4)2 · 3H2O | Orth. mmm (2/m 2/m 2/m) : Pmna |
19.12.20 | Reddingite | (Mn2+,Fe2+)3(PO4)2 · 3H2O | Orth. mmm (2/m 2/m 2/m) : Pmna |
19.12.21 | Earlshannonite | Mn2+Fe3+2(PO4)2(OH)2 · 4H2O | Mon. |
19.12.22 | Hureaulite | (Mn,Fe)5(PO4)2(HPO4)2 · 4H2O | Mon. 2/m : B2/b |
19.12.23 | Switzerite | (Mn,Fe)3(PO4)2 · 7H2O | Mon. |
19.12.24 | Laueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
19.12.25 | Pseudolaueite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O | Mon. 2/m : P21/b |
19.12.26 | Strunzite | Mn2+Fe3+2(PO4)2(OH)2 · 6H2O | Tric. 1 : P1 |
19.12.27 | Stewartite | Mn2+Fe3+2(PO4)2(OH)2 · 8H2O | Tric. 1 : P1 |
19.12.28 | Alluaudite | (Na,Ca)Mn2+(Fe3+,Mn2+,Fe2+,Mg)2(PO4)3 | Mon. |
19.12.29 | Ferroalluaudite | (Na,Ca)Fe2+(Fe3+,Mn2+,Fe2+)2(PO4)3 | |
19.12.30 | Fillowite | {Mn2+}{Na8}{Ca4Na4}{(Mn2+,Fe2+)43}(PO4)36 | Trig. 3 : R3 |
19.12.31 | Johnsomervilleite | Na10Ca6Mg18Fe25(PO4)36 | Trig. |
19.12.32 | Wicksite | NaCa2(Fe2+,Mn2+)4MgFe3+(PO4)6 · 2H2O | Orth. mmm (2/m 2/m 2/m) |
19.12.33 | Dickinsonite-(KMnNa) | {KNa}{Mn2+⃞}{Ca}{Na3}{Mn2+13}{Al}(PO4)12(OH)2 | Mon. 2/m : B2/b |
19.12.34 | Sarcopside | (Fe2+,Mn2+,Mg)3(PO4)2 | Mon. 2/m : P21/b |
19.12.35 | Ludlamite | Fe2+3(PO4)2 · 4H2O | Mon. 2/m : P21/b |
19.12.36 | Graftonite | Fe2+Fe2+2(PO4)2 | Mon. 2/m : P21/b |
19.12.37 | Wilhelmvierlingite | CaMnFe3+(PO4)2(OH) · 2H2O | Orth. |
19.12.38 | Fairfieldite | Ca2Mn2+(PO4)2 · 2H2O | Tric. 1 : P1 |
19.12.39 | Beusite | Mn2+Mn2+2 (PO4)2 | Mon. |
19.12.40 | Messelite | Ca2Fe2+(PO4)2 · 2H2O | Tric. 1 : P1 |
19.12.41 | Jahnsite-(CaMnFe) | {Ca}{Mn2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
19.12.42 | Jahnsite-(CaMnMn) | {Ca}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
19.12.43 | Jahnsite-(CaMnMg) | {Ca}{Mn2+}{(Mg,Fe2+)2}{Fe3+2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P2/b |
19.12.44 | Keckite | CaMn2+(Fe3+Mn2+)Fe3+2(PO4)4(OH)3 · 7H2O | Mon. 2/m : P2/b |
19.12.45 | Stanfieldite | Ca4Mg5(PO4)6 | Mon. |
19.12.46 | Laubmannite | (Fe2+,Mn2+,Ca)3Fe3+6(PO4)4(OH)12 | |
19.12.47 | Zodacite | Ca4Mn2+Fe3+4(PO4)6(OH)4 · 12H2O | Mon. |
19.12.48 | Hagendorfite | NaCaMn2+Fe2+2(PO4)3 | Mon. 2/m : B2/b |
19.12.49 | Maghagendorfite | (□,Na,)(Na,Ca,Fe2+)Mn(Mg,Fe2+,Fe3+)3(PO4)3 | Mon. |
19.12.50 | Varulite | NaCaMn2+Mn2+2(PO4)3 | Mon. 2/m : B2/b |
19.12.51 | Griphite | Na4Li2Ca6(Mn2+,Fe2+,Mg)19Al8(PO4)24(F,OH)8 | Iso. m3 (2/m 3) |
19.12.52 | Attakolite | (Ca,Sr)Mn(Al,Fe)4(HPO4,PO4)3(SiO4,PO4)(OH)4 | Mon. 2/m : B2/m |
19.12.53 | Arrojadite-(KFe) | {KNa}{Fe2+⃞}{Ca}{Na2⃞}{Fe2+13}{Al}(PO4)11(HPO4)(OH)2 | Mon. |
19.12.54 | Lun'okite | (Mn,Ca)(Mg,Fe,Mn)Al(PO4)2OH · 4H2O | Orth. mmm (2/m 2/m 2/m) : Pbca |
19.12.55 | Eosphorite | Mn2+Al(PO4)(OH)2 · H2O | Orth. mmm (2/m 2/m 2/m) : Cmca |
19.12.56 | Ernstite | (Mn2+,Fe3+)Al(PO4)(OH,O)2 · H2O | Mon. |
19.12.57 | Childrenite | Fe2+Al(PO4)(OH)2 · H2O | Orth. mm2 : Ccc2 |
19.12.58 | Bobfergusonite | Na2Mn5FeAl(PO4)6 | Mon. 2/m : P2/b |
19.12.59 | Qingheiite | NaMn3+Mg(Al,Fe3+)(PO4)3 | Mon. 2/m : P21/b |
19.12.60 | Whiteite-(CaFeMg) | {Ca}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P21/b |
19.12.61 | Whiteite-(CaMnMg) | {Ca}{Mn2+}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O | Mon. 2/m |
19.12.62 | Whiteite-(MnFeMg) | {(Mn2+,Ca)}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2O | Mon. 2/m : P21/b |
19.12.63 | Rittmannite | {(Mn2+,Ca)}{Mn2+}{(Fe2+,Mn2+,Mg)2}{(Al,Fe3+)2}(PO4)4(OH)2 · 8H2O | Mon. |
19.12.64 | Zanazziite | Ca2Mg5Be4(PO4)6(OH)4 · 6H2O | Mon. 2/m : B2/b |
19.12.65 | Samuelsonite | (Ca,Ba)Ca8Fe2+2Mn2+2Al2(PO4)10(OH)2 | Mon. 2/m : B2/m |
Fluorescence of Pararobertsite
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.
References for Pararobertsite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Roberts, Andrew C., Sturman, B. Darko, Dunn, P. J., and Roberts, Willard, L. (1989) Pararobertsite, Ca2 Mn3+3(PO4)3)2.3H2), a New Mineral Species from the Tip Top Pegmatite, Custer County, South Dakota, and its Relationship to Robertsite. Canadian Mineralogist: 27: 451-455.
Jambor, J.L., Puziewicz, J. (1990) New mineral names. American Mineralogist: 75: 1209-1216.
Kampf, A.R. (2000) The crystal structure of pararobertsite and its relationship to mitridatite. American Mineralogist: 85: 1302-1306.
Internet Links for Pararobertsite
mindat.org URL:
https://www.mindat.org/min-3108.html
Please feel free to link to this page.
Please feel free to link to this page.
External Links:
Mineral Dealers:
Localities for Pararobertsite
Locality List




All localities listed without proper references should be considered as questionable.
Poland | |
| Pieczka, A., Włodek, A., Gołębiowska, B., Szełęg, E., Szuszkiewicz, A., Ilnicki, S., Nejbert, K., Turniak, K. (2015): Phosphate-bearing pegmatites in the Góry Sowie Block and adjacent areas, Sudetes, SW Poland. 7th International Symposium on Granitic Pegmatites, PEG 2015 Książ, Poland. Abstracts: 77-78 |
| Pieczka, A., Włodek, A., Gołębiowska, B., Szełęg, E., Szuszkiewicz, A., Ilnicki, S., Nejbert, K., Turniak, K. (2015): Phosphate-bearing pegmatites in the Góry Sowie Block and adjacent areas, Sudetes, SW Poland. 7th International Symposium on Granitic Pegmatites, PEG 2015 Książ, Poland. Abstracts: 77-78 |
USA (TL) | |
| Nickel & Nichols, 1991, p160 - "Mineral Reference Manual" |
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Tip Top Mine, Fourmile, Custer District, Custer Co., South Dakota, USA