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Ferrorockbridgeite

A valid IMA mineral species
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04237140017272473122565.jpg
Ferrorockbridgeite

Hagendorf South Pegmatite, Hagendorf, Waidhaus, Neustadt an der Waldnaab District, Upper Palatinate, Bavaria, Germany
04237140017272473122565.jpg
Ferrorockbridgeite

Hagendorf South Pegmatite, Hagendorf, Waidhaus, Neustadt an der Waldnaab District, Upper Palatinate, Bavaria, Germany
04237140017272473122565.jpg
Ferrorockbridgeite

Hagendorf South Pegmatite, Hagendorf, Waidhaus, Neustadt an der Waldnaab District, Upper Palatinate, Bavaria, Germany
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About FerrorockbridgeiteHide

Formula:
(Fe2+,Mn2+)2(Fe3+)3(PO4)3(OH)4(H2O)
Colour:
Dark green to black.
Specific Gravity:
3.21 - 3.33
Crystal System:
Orthorhombic
Name:
Iron analogue of rockbridgeite.
The Fe2+ analogue of manganrockbridgeite.


Unique IdentifiersHide

Mindat ID:
52914
Long-form identifier:
mindat:1:1:52914:9

Similar NamesHide

FerrirockbridgeiteA valid IMA mineral species(Fe3+0.67◻0.33)2(Fe3+)3(PO4)3(OH)4(H2O)

IMA Classification of FerrorockbridgeiteHide

Classification of FerrorockbridgeiteHide

Strunz-mindat (2026):
8.BC.10

8 : PHOSPHATES, ARSENATES, VANADATES
B : Phosphates, etc., with additional anions, without H2O
C : With only medium-sized cations, (OH, etc.):RO4 > 1:1 and < 2:1

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference for Standard
ForckIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of FerrorockbridgeiteHide

Colour:
Dark green to black.
Density:
3.21 - 3.33 g/cm3 (Measured)    3.51 g/cm3 (Calculated)
Comment:
Measured using Berman balance with toluene. The low measured value is due to sub-micron porosity.

Optical Data of FerrorockbridgeiteHide

Type:
Biaxial (-)
RI values:
nα = 1.763(3) nβ = 1.781 nγ = 1.797(3)
2V:
Measured: 87° (1)
Max. Birefringence:
δ = 0.034
Based on recorded range of RI values above.

Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.

Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.

Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.

Surface Relief:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).

This shows the grain boundary and Becke line effect under plane-polarised light, based on the contrast between this mineral's average refractive index and the mounting medium. It does not take into account mineral colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure - the conoscopic view for a grain cut perpendicular to the acute bisectrix, using this mineral's 2V. The two small white dots mark the melatopes - the points where the two optic axes emerge - and are shown only when they fall within the field of view. The coloured bands are isochromatics, and the dark bands are isogyres.

Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
Strong
Pleochroism:
Visible
Comments:
X = blue green, Y = olive green, Z = yellow brown.
Comments:
β is calculated.
X = c, Y = a, Z = b.
Absorption X ≈ Y > Z.

Chemistry of FerrorockbridgeiteHide

Mindat Formula:
(Fe2+,Mn2+)2(Fe3+)3(PO4)3(OH)4(H2O)
Element Weights:
Element% weight
Fe42.946 %
O41.833 %
P14.292 %
H0.930 %

Calculated from ideal end-member formula.
Fe
O
P
H
Elements listed:
Fe, H, Mn, O, P - search for minerals with similar chemistry

Crystallography of FerrorockbridgeiteHide

Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Cell Parameters:
a = 13.994(1) Å, b = 16.884(1) Å, c = 5.1866(4) Å
Ratio:
a:b:c = 0.829 : 1 : 0.307
Unit Cell V:
1,225.46 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Blades are flattened on {010} and elongated on [001].
Comment:
Space group is Bbmm

X-Ray Powder DiffractionHide

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Near-surface Processes
22 : Hydration and low-? subsurface aqueous alteration (see also #23)
Stage 4b: Highly evolved igneous rocks>3.0
34 : Complex granite pegmatites
Stage 7: Great Oxidation Event<2.4
47a : [Near-surface hydration of prior minerals]
47c : [Carbonates, phosphates, borates, nitrates]

Type Occurrence of FerrorockbridgeiteHide

Type Locality:
ⓘ Hagendorf South Pegmatite, Hagendorf, Waidhaus, Neustadt an der Waldnaab District, Upper Palatinate, Bavaria, Germany
General Appearance of Type Material:
Densely packed, lustrous, black blades. Individual blades are up to 2 mm in length and roughly 10 µm thick.
Place of Conservation of Type Material:
Mineralogical collections of the Museum Victoria, 11 Nicholson St, Carlton, VIC 3053, Australia, registration number M54126 (holotype), and the Natural History Museum of Los Angeles County, Los Angeles, California, USA, catalogue nr 67281 (cotype).
Geological Setting of Type Material:
Zoned granitic phosphate pegmatite.
Associated Minerals at Type Locality:
Jahnsite SubgroupLaueiteMitridatiteSchoonerite Group
Reference:
Grey, Ian E., Kampf, Anthony R., Keck, Erich, Cashion, John D., MacRae, Colin M., Gozukara, Yesim, Peterson, Vanessa K., Shanks, Finlay L. (2019) The rockbridgeite group approved and a new member, ferrorockbridgeite, (Fe2+,Mn2+)2(Fe3+)3(PO4)3(OH)4(H2O), described from the Hagendorf Süd pegmatite, Oberpfalz, Bavaria. European Journal of Mineralogy, 31 (2) 389-397 doi:10.1127/ejm/2019/0031-2823

Synonyms of FerrorockbridgeiteHide

Other Language Names for FerrorockbridgeiteHide

Relationship of Ferrorockbridgeite to other SpeciesHide

Member of:
Rockbridgeite Group
Other Members of Rockbridgeite Group:
Ferrirockbridgeite(Fe3+0.67◻0.33)2(Fe3+)3(PO4)3(OH)4(H2O)Orth. mmm(2/m2/m2/m)
Frondelite(Mn2+0.5Fe3+0.5)2Fe3+3(PO4)3(OH)5Orth. 222 : C2221
ManganrockbridgeiteMn2+2Fe3+3(PO4)3(OH)4(H2O)Mon. 2/m : P21/m
PlimeriteZnFe3+4(PO4)3(OH)5Orth. mmm(2/m2/m2/m)
Rockbridgeite(Fe2+0.5Fe3+0.5)2Fe3+3(PO4)3(OH)5Orth. mmm(2/m2/m2/m)

Related Minerals - Strunz-mindat GroupingHide

8.BC.ManganrockbridgeiteMn2+2Fe3+3(PO4)3(OH)4(H2O)Mon. 2/m : P21/m
8.BC.Elaliite(Fe2+8Fe3+)(PO4)O8Orth. mmm(2/m2/m2/m) : Cmmm
8.BC.ElkinstantoniteFe4(PO4)2OMon. 2/m : P21/c
8.BC.05Leybovite-KKCuNa(MgFe3+)(AsO4)3Mon. 2/m : B2/b
8.BC.05AngelelliteFe3+4(AsO4)2O3Tric. 1 : P1
8.BC.10Frondelite(Mn2+0.5Fe3+0.5)2Fe3+3(PO4)3(OH)5Orth. 222 : C2221
8.BC.10Rockbridgeite(Fe2+0.5Fe3+0.5)2Fe3+3(PO4)3(OH)5Orth. mmm(2/m2/m2/m)
8.BC.10Ferrirockbridgeite(Fe3+0.67◻0.33)2(Fe3+)3(PO4)3(OH)4(H2O)Orth. mmm(2/m2/m2/m)
8.BC.10PlimeriteZnFe3+4(PO4)3(OH)5Orth. mmm(2/m2/m2/m)
8.BC.15AerugiteNi8.5(AsO4)2As5+O8Trig. 3m(32/m) : R3m

Other InformationHide

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 FerrorockbridgeiteHide

References for FerrorockbridgeiteHide

Localities for FerrorockbridgeiteHide

Showing 2 localities.

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.
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Locality ListHide

- 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.
Germany (TL)
 
  • Bavaria
    • Upper Palatinate
      • Neustadt an der Waldnaab District
        • Waidhaus
          • Hagendorf
Hålenius et al. (2018) +1 other reference
USA
 
  • Maine
    • Oxford County
      • Paris
SEM/EDS analyzed by Lloyd W. Alexander ... +1 other reference
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