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Jahnsite-(NaFeMg)

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About Jahnsite-(NaFeMg)Hide

Richard H. Jahns
Formula:
NaFe3+Mg2Fe3+2(PO4)4(OH)2 · 8H2O
Colour:
yellow, orange-red
Lustre:
Vitreous
Hardness:
4
Specific Gravity:
2.58
Crystal System:
Monoclinic
Name:
For the mineral jahnsite and its sodium, iron and magnesium content.

The root name is in honor of Richard Henry Jahns (March 10, 1915 Los Angeles, California, USA - December 31, 1983 Palo Alto, California, USA), mineralogist and pegmatite expert, Stanford University, Palo Alto, California, USA.

Classification of Jahnsite-(NaFeMg)Hide

Approved
Approval Year:
2007
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
42.11.2.6

42 : HYDRATED PHOSPHATES, ETC.CONTAINING HYDROXYL OR HALOGEN
11 : (AB)3(XO4)2Zq·xH2O

Physical Properties of Jahnsite-(NaFeMg)Hide

Vitreous
Transparency:
Transparent
Colour:
yellow, orange-red
Comment:
orange-red bands near their terminations
Streak:
White
Hardness:
Tenacity:
Brittle
Cleavage:
Distinct/Good
{001}
Fracture:
Splintery
Density:
2.58(2) g/cm3 (Measured)    2.608 g/cm3 (Calculated)

Optical Data of Jahnsite-(NaFeMg)Hide

Type:
Biaxial (-)
RI values:
nα = 1.632(1) nβ = 1.669(1) nγ = 1.671(1)
2V:
Measured: 25° (5), Calculated: 26°
Max Birefringence:
δ = 0.039
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:
Moderate
Dispersion:
r > v, very strong
Pleochroism:
Visible
Comments:
X = colorless, Y and Z = beige; Y = Z > X.

Chemical Properties of Jahnsite-(NaFeMg)Hide

Formula:
NaFe3+Mg2Fe3+2(PO4)4(OH)2 · 8H2O
IMA Formula:
NaFe3+Mg2Fe3+2(PO4)4(OH)2 · 8H2O

Crystallography of Jahnsite-(NaFeMg)Hide

Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P2/b
Setting:
P2/a
Cell Parameters:
a = 15.0811(16) Å, b = 7.1403(8) Å, c = 9.8299(11) Å
β = 110.445(1)°
Ratio:
a:b:c = 2.112 : 1 : 1.377
Unit Cell V:
991.84 ų (Calculated from Unit Cell)
Z:
2
Twinning:
simple contact and polysynthetic by reflection on {001}. The twinning combines with the prism forms {011} and {001} and the terminal form {100} to yield six-sided pseudo-orthorhombic prisms with shallow wedge-like terminations

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
9.218 (100)
4.884 (25)
3.537 (25)
2.973 (25)
2.854 (20)
2.819 (70)
2.593 (25)
1.933 (20)

Type Occurrence of Jahnsite-(NaFeMg)Hide

General Appearance of Type Material:
prismatic along [100]
Place of Conservation of Type Material:
mineral collection of the Natural History Museum of Los Angeles County (catalog numbers 58590, 58591, and 58592).
Geological Setting of Type Material:
highly altered and oxidized triphylite pod from pegmatite
Associated Minerals at Type Locality:

Synonyms of Jahnsite-(NaFeMg)Hide

Other Language Names for Jahnsite-(NaFeMg)Hide

Relationship of Jahnsite-(NaFeMg) to other SpeciesHide

Other Members of this group:
Jahnsite-(CaFeFe){Ca}{Fe2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon.
Jahnsite-(CaFeMg)CaFe2+Mg2Fe3+2(PO4)4(OH)2·8H2OMon. 2/m : P2/b
Jahnsite-(CaMnFe){Ca}{Mn2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
Jahnsite-(CaMnMg){Ca}{Mn2+}{(Mg,Fe2+)2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
Jahnsite-(CaMnMn){Ca}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
Jahnsite-(MnMnFe2+)MnMn2+Fe2+2Fe3+2(PO4)4(OH)2·8H2O
Jahnsite-(MnMnMg)Mn2+Mn2+Mg2Fe3+2(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
Jahnsite-(MnMnMn){Mn2+}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon.
Jahnsite-(MnMnZn)Mn2+Mn2+Zn2Fe3+2(PO4)4(OH)2·8H2OMon. 2/m : P2/b
Jahnsite-(NaMnMg){(Na,Ca)}{(Mn2+,Fe3+)}{(Mg,Fe3+)2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b

Common AssociatesHide

Associated Minerals Based on Photo Data:
Jahnsite-(CaMnMg)2 photos of Jahnsite-(NaFeMg) associated with Jahnsite-(CaMnMg) on mindat.org.
Jahnsite-(NaMnMg)2 photos of Jahnsite-(NaFeMg) associated with Jahnsite-(NaMnMg) on mindat.org.
Jahnsite-(CaMgMg)2 photos of Jahnsite-(NaFeMg) associated with Jahnsite-(CaMgMg) on mindat.org.
Messelite2 photos of Jahnsite-(NaFeMg) associated with Messelite on mindat.org.

Related Minerals - Nickel-Strunz GroupingHide

8.DH.05MinyuliteKAl2(PO4)2(OH,F) · 4H2OOrth. mm2 : Pba2
8.DH.10LeucophosphiteKFe3+2(PO4)2(OH) · 2H2OMon. 2/m : P21/b
8.DH.10Spheniscidite(NH4,K)(Fe3+,Al)2(PO4)2(OH) · 2H2OMon.
8.DH.10TinsleyiteKAl2(PO4)2(OH) · 2H2OMon.
8.DH.15Jahnsite-(CaMnFe){Ca}{Mn2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
8.DH.15Jahnsite-(CaMnMg){Ca}{Mn2+}{(Mg,Fe2+)2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
8.DH.15Jahnsite-(CaMnMn){Ca}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
8.DH.15KeckiteCaMn2+(Fe3+Mn2+)Fe3+2(PO4)4(OH)3 · 7H2OMon. 2/m : P2/b
8.DH.15Rittmannite{(Mn2+,Ca)}{Mn2+}{(Fe2+,Mn2+,Mg)2}{(Al,Fe3+)2}(PO4)4(OH)2 · 8H2OMon.
8.DH.15Whiteite-(CaFeMg){Ca}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2OMon. 2/m : P21/b
8.DH.15Whiteite-(CaMnMg){Ca}{Mn2+}{Mg2}{Al2}(PO4)4(OH)2 · 8H2OMon. 2/m
8.DH.15Whiteite-(MnFeMg){(Mn2+,Ca)}{(Fe2+,Mn2+)}{Mg2}{Al2}(PO4)4(OH)2 · 8H2OMon. 2/m : P21/b
8.DH.15Jahnsite-(MnMnMn){Mn2+}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon.
8.DH.15Kaluginite(Mn2+,Ca)MgFe3+(PO4)2(OH) · 4H2OOrth.
8.DH.15Jahnsite-(CaFeFe){Ca}{Fe2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon.
8.DH.15Jahnsite-(NaMnMg){(Na,Ca)}{(Mn2+,Fe3+)}{(Mg,Fe3+)2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
8.DH.15Jahnsite-(CaMgMg){Ca}{Mg}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O
8.DH.20Manganosegelerite(Mn2+,Ca)(Mn2+,Fe2+,Mg)Fe3+(PO4)2(OH) · 4H2OOrth. mmm (2/m 2/m 2/m) : Pbca
8.DH.20OveriteCaMgAl(PO4)2(OH) · 4H2OOrth. mmm (2/m 2/m 2/m) : Pbca
8.DH.20SegeleriteCa2 Mg2 Fe3+2(PO4)4(OH)2 · 8H2OOrth. mmm (2/m 2/m 2/m) : Pcca
8.DH.20WilhelmvierlingiteCaMnFe3+(PO4)2(OH) · 2H2OOrth.
8.DH.20JuonniiteCaMgSc(PO4)2(OH) · 4H2OOrth.
8.DH.25CalcioferriteCa2Fe3+2(PO4)3(OH) · 7H2OMon. 2/m : B2/b
8.DH.25KingsmountiteCa4(Fe2+,Mn2+)Al4(PO4)6(OH)4 · 12H2OMon. 2 : B2
8.DH.25MontgomeryiteCa4MgAl4(PO4)6(OH)4 · 12H2OMon. 2 : B2
8.DH.25ZodaciteCa4Mn2+Fe3+4(PO4)6(OH)4 · 12H2OMon.
8.DH.30ArseniosideriteCa2Fe3+3(AsO4)3O2 · 3H2OMon. 2/m : B2/b
8.DH.30KolfaniteCa2Fe3+3O2(AsO4)3 · 2H2OMon.
8.DH.30MitridatiteCa2Fe3+3(PO4)3O2 · 3H2OMon. 2/m : B2/b
8.DH.30PararobertsiteCa2Mn3+3(PO4)3O2 · 3H2OMon. 2/m : P21/b
8.DH.30RobertsiteCa2Mn3+3(PO4)3O2 · 3H2OMon. m : Bb
8.DH.30Sailaufite(Ca,Na,☐)2Mn3+3(AsO4)2(CO3)O2 · 3H2OMon.
8.DH.35MantienneiteKMg2Al2Ti(PO4)4(OH)3 · 15H2OOrth.
8.DH.35PaulkerriteK(Mg,Mn2+)2(Fe3+,Al,Ti,Mg)2Ti(PO4)4(OH)3 · 15H2OOrth. mmm (2/m 2/m 2/m) : Pbca
8.DH.35Benyacarite(H2O,K)2(Mn2+,Fe2+)2(Fe3+,Ti)2Ti(PO4)4(O,F)2 · 14H2OOrth. mmm (2/m 2/m 2/m) : Pbca
8.DH.40XanthoxeniteCa4Fe3+2(PO4)4(OH)2 · 3H2OTric. 1 : P1
8.DH.45MahnertiteNaCu3(AsO4)2Cl · 5H2OTet. 4/mmm (4/m 2/m 2/m) : I4/mmm
8.DH.50AndyrobertsiteKCdCu5(AsO4)4(H2AsO4) · 2H2OMon.
8.DH.50CalcioandyrobertsiteKCaCu5(AsO4)4(H2AsO4) · 2H2OMon. 2/m : P21/m
8.DH.55EnglishiteK3Na2Ca10Al15(PO4)21(OH)7 · 26H2OMon. 2/m
8.DH.60BouazzeriteBi6(Mg,Co)11Fe3+14(AsO4)18(OH)4O12 · 86H2OMon. 2/m

Related Minerals - Dana Grouping (8th Ed.)Hide

42.11.2.1Jahnsite-(CaMnMg){Ca}{Mn2+}{(Mg,Fe2+)2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
42.11.2.2Jahnsite-(CaMnFe){Ca}{Mn2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
42.11.2.3Jahnsite-(CaMnMn){Ca}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
42.11.2.4Jahnsite-(MnMnMn){Mn2+}{Mn2+}{Mn2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon.
42.11.2.5Jahnsite-(CaFeFe){Ca}{Fe2+}{Fe2+2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon.
42.11.2.8Jahnsite-(NaMnMg){(Na,Ca)}{(Mn2+,Fe3+)}{(Mg,Fe3+)2}{Fe3+2}(PO4)4(OH)2 · 8H2OMon. 2/m : P2/b
42.11.2.9Jahnsite-(CaMgMg){Ca}{Mg}{Mg2}{Fe3+2}(PO4)4(OH)2 · 8H2O

Other InformationHide

Notes:
Crystals slowly dissolve in cold dilute HCl
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 Jahnsite-(NaFeMg)Hide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
A.R. Kampf, I.M. Steele, & T.A. Loomis (2008): Jahnsite-(NaFeMg), a new mineral from the Tip Top mine, custer County, South Dakota: Description and crystal structure. Am. Mineral. 93, 940-945.

Internet Links for Jahnsite-(NaFeMg)Hide

Localities for Jahnsite-(NaFeMg)Hide

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for 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 (eg from pseudomorphs.)

All localities listed without proper references should be considered as questionable.
Australia
 
  • South Australia
    • Mt Lofty Ranges
      • North Mt Lofty Ranges
        • Kapunda
Peter Elliott
Morocco
 
  • Drâa-Tafilalet Region
    • Ouarzazate Province
      • Tazenakht
Kampf, A.R., Mills, S.J., Housley, R.M., Favreau, G., Boulliard, J-C, and Bourgoin, V. (2012) Angarfite, a new mineral species from the Angarf-sud pegmatite, Morocco : description and crystal structure. The Canadian Mineralogist Vol. 50, pages 781-791. DOI 10.3749/canmin.50.4.781
USA (TL)
 
  • South Dakota
    • Custer Co.
      • Custer District
        • Fourmile
A.R. Kampf, I.M. Steele, & T.A. Loomis (2008): Jahnsite-(NaFeMg), a new mineral from the Tip Top mine, custer County, South Dakota: Description and crystal structure. Am. Mineral. 93, 940-945.
Mineral and/or Locality  
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