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About Ferro-gedriteHide

The gedrite group are orthorhombic amphiboles in the magnesium-iron-manganese amphibole subgroup defined with A(Na+K+2Ca)<0.5 apfu and C(Al+Fe3++2Ti)>1 apfu

Ferro-gedrite is defined with Fe2+ as the dominant element both in the B and C2+ positions and Al in the C3+ position.
Pale greenish-grey to brown
5½ - 6
Crystal System:
For its relationship to gedrite
This page provides mineralogical data about Ferro-gedrite.

Classification of Ferro-gedriteHide

Approved, 'Grandfathered' (first described prior to 1959)

9 : SILICATES (Germanates)
D : Inosilicates
D : Inosilicates with 2-periodic double chains, Si4O11; Orthoamphiboles

16 : Silicates Containing Aluminum and other Metals
19 : Aluminosilicates of Fe and Mg

Physical Properties of Ferro-gedriteHide

Pale greenish-grey to brown
5½ - 6 on Mohs scale

Optical Data of Ferro-gedriteHide

Biaxial (-)
RI values:
nα = 1.642 - 1.694 nβ = 1.649 - 1.710 nγ = 1.661 - 1.722
Measured: 82° , Calculated: 76° to 80°
Max Birefringence:
δ = 0.019 - 0.028
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
Surface Relief:
r > v or r < v

Chemical Properties of Ferro-gedriteHide


The gedrite group are orthorhombic amphiboles in the magnesium-iron-manganese amphibole subgroup defined with A(Na+K+2Ca)<0.5 apfu and C(Al+Fe3++2Ti)>1 apfu

Ferro-gedrite is defined with Fe2+ as the dominant element both in the B and C2+ positions and Al in the C3+ position.
IMA Formula:
Common Impurities:

Crystallography of Ferro-gedriteHide

Crystal System:
Cell Parameters:
a = 18.52 Å, b = 17.94 Å, c = 5.31 Å
a:b:c = 1.032 : 1 : 0.296
Unit Cell V:
1,764.24 ų (Calculated from Unit Cell)

Other Language Names for Ferro-gedriteHide

Relationship of Ferro-gedrite to other SpeciesHide

Common AssociatesHide

Associated Minerals Based on Photo Data:
Siderophyllite1 photo of Ferro-gedrite associated with Siderophyllite on mindat.org.
Gehlenite1 photo of Ferro-gedrite associated with Gehlenite on mindat.org.
Chlorite Group1 photo of Ferro-gedrite associated with Chlorite Group on mindat.org.
Talc1 photo of Ferro-gedrite associated with Talc on mindat.org.

Related Minerals - Nickel-Strunz GroupingHide

9.DD.05Anthophyllite☐{Mg2}{Mg5}(Si8O22)(OH)2Orth. mmm (2/m 2/m 2/m) : Pnma
9.DD.05Proto-anthophyllite☐{Mg2}{Mg5}(Si8O22)(OH)2Orth. mmm (2/m 2/m 2/m) : Pnnm

Related Minerals - Hey's Chemical Index of Minerals GroupingHide

16.19.1IndialiteMg2Al3(AlSi5O18)Hex. 6/mmm (6/m 2/m 2/m) : P6/mcc
16.19.2Cordierite(Mg,Fe)2Al3(AlSi5O18)Orth. mmm (2/m 2/m 2/m) : Cccm
16.19.5StauroliteFe2+2Al9Si4O23(OH)Mon. 2/m : B2/m
16.19.6Chloritoid(Fe2+,Mg,Mn2+)Al2(SiO4)O(OH)2Mon. 2/m : B2/b
16.19.7AmesiteMg2Al(AlSiO5)(OH)4Tric. 1 : P1
16.19.9YoderiteMg(Al,Fe3+)3(SiO4)2O(OH)Mon. 2/m : P21/m
16.19.11Ferrocarpholite(Fe2+,Mg)Al2(Si2O6)(OH)4Orth. mmm (2/m 2/m 2/m) : Ccca
16.19.15Berthierine(Fe2+,Fe3+,Al)3(Si,Al)2O5(OH)4Mon. m : Bm
16.19.16Odinite(Fe,Mg,Al,Fe,Ti,Mn)2.4((Si,Al)2O5)(OH)4Mon. m : Bm
16.19.17ClinochloreMg5Al(AlSi3O10)(OH)8Mon. 2/m : B2/m
16.19.22VermiculiteMg0.7(Mg,Fe,Al)6(Si,Al)8O20(OH)4 · 8H2OMon. 2/m
16.19.23Corrensite(Mg,Fe)9((Si,Al)8O20)(OH)10 · nH2OOrth.

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.

References for Ferro-gedriteHide

Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Mandarino, J.A. (1998) The Second List of Additions and Corrections to the Glossary of Mineral Species (1995). The Amphibole Group. Mineralogical Record: 29: 169-174.
Hawthorne, F.C., Oberti, R. (2006) On the classification of amphiboles. The Canadian Mineralogist: 44: 1-21.
Hawthorne, F.C., Oberti, R., Harlow, G.E., Maresch, W.V., Martin, R.F., Schumacher, J.C., Welch, M.D. (2012) Nomenclature of the amphibole supergroup. American Mineralogist: 97: 2031-2048.

Internet Links for Ferro-gedriteHide

Localities for Ferro-gedriteHide

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.
Czech Republic
  • Vysočina Region
    • Žďár nad Sázavou District
      • Křižanov
Schreyer, W., Bernhardt, H.-J., Medenbach, O.: Ferrogedrite, siderophyllite, septechamosite, andalusite and chloritoid as alteration products of sekaninaite (ferrocordierite) from the Dolní Bory pegmatite, Moravia. Russian Geology and Geophysics, 1993, 34, 12, 125-131.
Staněk, J.: Asociace minerálů významnějších pegmatitových žil v Hatích u Dolních Borů na západní Moravě. Acta Musei Moraviae, Scientiae naturales, 1997, roč. 82, 3-19.
  • Greenland
    • Sermersooq
      • Nuuk (Godthåb)
Petersen, O. V. & Secher, K. (1993): The Minerals of Greenland. Mineralogical Record 24 (2): 1-67
  • Pirkanmaa
    • Orivesi
  • Lower Saxony
    • Harz
      • Bad Harzburg
Baumgärtl,U. (2014) Der Diabassteinbruch Huneberg im Oberharz. Der Aufschluss, Jg. 65, Nr. 04, Seite 240-260
  • Schleswig-Holstein
    • Brunsbüttel
A. Wittern: "Mineralfundorte in Deutschland", Schweizerbart (Stuttgart), 2001
    • Elmshorn
      • Barmstedt
A. Wittern: "Mineralfundorte in Deutschland", Schweizerbart (Stuttgart), 2001
  • Rajasthan (Rajputana)
    • Jaipur Division
      • Jhunjhunu District
Mineralogical Magazine (1967) 36 ,22-28
  • Gifu
    • Ena City
Bulletin of the National Science Museum, Ser. C, 6(4), 107-113 (Tokyo); RRUFF Project specimen ID # R060330; Forrest Cureton and Excalibur Mineral Co. specimens.
  • Iwate
    • Tono City
      • Miyamori
Seki, Y., and Yamasaki, M. (1957): American Mineralogist 42, 506-520.
  • Akershus
    • Ullensaker
Terje Karstensen collection (pers.info. to Knut Edvard Larsen 16.10.2014), specimen analyzed; Larsen, K. E. (2015). Noen funn av mineraler i Norge 2013-2015. Norsk Mineralsymposium 2015, 79-88.
  • New Hampshire
    • Carroll Co.
      • Hale's Location
Smith, Arthur E. (2005): New Hampshire Mineral Locality Index (Rocks & Minerals 80:242-261)
  • New York
John H. Betts (2009) "The minerals of New York City", Rocks & Minerals, 84, 204-240.
  • Wisconsin
    • Jackson Co.
William S. Cordua collection
Mineral and/or Locality  
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