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Ferrirockbridgeite

A valid IMA mineral species
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02836680017670622308030.jpg
Ferrirockbridgeite, etc.

Palermo No. 1 Mine, Groton, Grafton County, New Hampshire, USA
02836680017670622308030.jpg
Ferrirockbridgeite, etc.

Palermo No. 1 Mine, Groton, Grafton County, New Hampshire, USA
02836680017670622308030.jpg
Ferrirockbridgeite, etc.

Palermo No. 1 Mine, Groton, Grafton County, New Hampshire, USA
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About FerrirockbridgeiteHide

Formula:
(Fe3+0.67◻0.33)2(Fe3+)3(PO4)3(OH)4(H2O)
Colour:
Reddish-brown
Specific Gravity:
3.33
Crystal System:
Orthorhombic
Name:
For the root name of rockbridgeite and the ferric iron content.
Fe3+-vacancy-analogue of ferrorockbridgeite. One of few known fully ferric-iron hydrous hydrated phosphate minerals, chemically comparable to allanpringite, beraunite, ferristrunzite, santabarbaraite, and tinticite.


Unique IdentifiersHide

Mindat ID:
53168
Long-form identifier:
mindat:1:1:53168:5

Similar NamesHide

FerrorockbridgeiteA valid IMA mineral species(Fe2+,Mn2+)2(Fe3+)3(PO4)3(OH)4(H2O)

IMA Classification of FerrirockbridgeiteHide

Classification of FerrirockbridgeiteHide

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

Physical Properties of FerrirockbridgeiteHide

Colour:
Reddish-brown
Density:
3.33 g/cm3 (Measured)    3.42 g/cm3 (Calculated)
Comment:
Measured using Berman balance with toluene. The low measured value is due to sub-micron porosity.

Optical Data of FerrirockbridgeiteHide

Type:
Biaxial (-)
RI values:
nα = 1.875(5) nβ = 1.890 nγ = 1.900(5)
2V:
Measured: 78° (1)
Max. Birefringence:
δ = 0.025
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:
Moderate
Dispersion:
Strong, with r > v
Pleochroism:
Visible
Comments:
X = yellow brown, Y = olive brown, Z = dark olive green
Comments:
β calculated.
Orientation: X = c, Y = a, Z = b.
Absorption: Z > Y > X.

Chemistry of FerrirockbridgeiteHide

Mindat Formula:
(Fe3+0.67◻0.33)2(Fe3+)3(PO4)3(OH)4(H2O)
Element Weights:
Element% weight
O44.347 %
Fe39.517 %
P15.150 %
H0.986 %

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

Crystallography of FerrirockbridgeiteHide

Crystal System:
Orthorhombic
Class (H-M):
mmm(2/m2/m2/m) - Dipyramidal
Cell Parameters:
a = 13.853(1) Å, b = 16.928(1) Å, c = 5.1917(5) Å
Ratio:
a:b:c = 0.818 : 1 : 0.307
Unit Cell V:
1,217.47 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Blade-like crystals, 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 FerrirockbridgeiteHide

Type Locality:
ⓘ Palermo No. 1 Mine, Groton, Grafton County, New Hampshire, USA
General Appearance of Type Material:
Radial fibrous crusts and masses. Compact intergrowths of reddish-brown blade-like crystals.
Place of Conservation of Type Material:
Collections of the Mineralogical and Geological Museum, Harvard University, 20 Oxford Street, Cambridge, MA 02138, USA, catalogue number 95086.
Geological Setting of Type Material:
Oxidized zone of a granitic pegmatite. Highly oxidized alteration of triphylite.
Associated Minerals at Type Locality:
Rockbridgeite
Reference:
Grey, Ian Edward, Kampf, Anthony R., Keck, Erich, Cashion, John D., MacRae, Colin M., Gozukara, Yesim, Shanks, Finlay L. (2019) Ferrirockbridgeite, (Fe3+0.67□0.33)2(Fe3+)3(PO4)3(OH)4(H2O), and the oxidation mechanism for rockbridgeite-group minerals. European Journal of Mineralogy, 31 (3) 585-594 doi:10.1127/ejm/2019/0031-2846

Synonyms of FerrirockbridgeiteHide

Other Language Names for FerrirockbridgeiteHide

Relationship of Ferrirockbridgeite to other SpeciesHide

Member of:
Rockbridgeite Group
Other Members of Rockbridgeite Group:
Ferrorockbridgeite(Fe2+,Mn2+)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)

Common AssociatesHide

Associations Based on Photo Data:
3 photos of Ferrirockbridgeite associated with Rockbridgeite(Fe2+0.5Fe3+0.5)2Fe3+3(PO4)3(OH)5
3 photos of Ferrirockbridgeite associated with SideriteFeCO3

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/b
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.10Ferrorockbridgeite(Fe2+,Mn2+)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 FerrirockbridgeiteHide

References for FerrirockbridgeiteHide

Localities for FerrirockbridgeiteHide

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
 
  • Bavaria
    • Upper Palatinate
      • Neustadt an der Waldnaab District
        • Waidhaus
          • Hagendorf
Grey et al. (2019)
USA (TL)
 
  • New Hampshire
    • Grafton County
      • Groton
Grey et al. (2019)
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